<PAGE>   1



                       SECURITIES AND EXCHANGE COMMISSION
                             Washington D.C. 20549


                                   FORM 10-Q

(Mark One)

{X}     Quarterly report pursuant to Section 13 or 15(d) of the 
        Securities Exchange Act of 1934

        For the quarterly period ended November 30, 1998.

[ ]     Transition report pursuant to Section 13 or 15(d) of the 
        Securities Exchange Act of 1934

        For the transition period from _______________ to ______________.

Commission file number:  0-21308

                              JABIL CIRCUIT, INC.

             (Exact name of registrant as specified in its charter)

               DELAWARE                             38-1886260
 (State or other jurisdiction of                 (I.R.S. Employer
   incorporation or organization)                Identification No.)

                             10800 Roosevelt Blvd.
                            St. Petersburg, FL 33716
          (Address of principal executive offices, including zip code)

Registrant's Telephone No., including area code:  (727) 577-9749

                        --------------------------------

Indicate by check mark whether the Registrant (1) has filed all reports
required to be filed by Section 13 or 15(d) of the Securities Exchange Act of
1934 during the preceding 12 months (or for such shorter period that the
Registrant was required to file such reports), and (2) has been subject to such
filing requirements for the past 90 days:

                                  Yes X   No 
                                     ---     ---
         As of January 6, 1999, there were 37,319,175 shares of the
Registrant's Common Stock outstanding.




<PAGE>   2

                      JABIL CIRCUIT, INC. AND SUBSIDIARIES

                                     INDEX



                         PART I. FINANCIAL INFORMATION


<TABLE>

<S>  <C>                                                                                                        <C>

Item 1.       Financial Statements

              Consolidated Balance Sheets at
              August 31, 1998 and November 30, 1998.......................................................        3 
                                                                                                               
              Consolidated Statements of Earnings for the three months                                         
              ended November 30, 1998.....................................................................        4   
                                                                                                               
              Consolidated Statements of Cash Flows                                                            
              for the three months ended November 30, 1998................................................        5  
                                                                                                               
              Notes to Consolidated Financial Statements..................................................        6
                                                                                                               

Item 2.       Management's Discussion and Analysis of                                                          
              Financial Condition and Results of Operations...............................................        9
                                                                                                               
                                                                                                               
                                                                                                               

PART II.  OTHER INFORMATION                                                                                    
                                                                                                               

Item 6.       Exhibits and Reports on Form 8-K............................................................       12
                                                                                                               
                                                                                                               
              Signatures..................................................................................       12



</TABLE>




                                       2


<PAGE>   3

 PART I.  FINANCIAL INFORMATION


                     JABIL CIRCUIT, INC. AND SUBSIDIARIES
                         CONSOLIDATED BALANCE SHEETS
                                (IN THOUSANDS)




                                                August 31,   November 30,
                                                  1998          1998
                                                ----------   ------------
                                                             (Unaudited) 
[S]                                             [C]          [C]   
ASSETS
Current assets
  Cash                                          $ 23,139     $ 13,016
  Accounts receivable - Net                      126,276      180,793
  Inventories                                    123,097      146,272
  Prepaid expenses and other current assets        1,772        3,367
  Deferred income taxes                           16,095       14,960
                                                --------     --------

        Total current assets                     290,379      358,408


Property, plant and equipment, net               224,680      246,496
Other assets                                      11,644       11,405
                                                --------     --------

                                                $526,703     $616,309
                                                ========     ========

LIABILITIES AND STOCKHOLDERS' EQUITY
Current liabilities
  Current installments of long term debt        $  8,333     $  8,333
  Accounts payable                               132,601      192,764
  Accrued expenses                                40,460       43,939
  Income taxes payable                             5,325       10,908
                                                --------     --------

        Total current liabilities                186,719      255,944


Long term debt, less current installments         81,667       81,667
Deferred income taxes                              7,724        8,484
Deferred grant revenue                             2,227        2,421
                                                --------     --------

        Total liabilities                        278,337      348,516
                                                --------     --------

Stockholders' equity
  Common stock                                        37           37
  Additional paid-in capital                      71,580       71,721
  Retained earnings                              176,749      196,035
                                                --------     --------

        Total stockholders' equity               248,366      267,793

                                                $526,703     $616,309
                                                ========     ========





          See Accompanying Notes to Consolidated Financial Statements



                                       3

<PAGE>   4
                      JABIL CIRCUIT, INC. AND SUBSIDIARIES
                      CONSOLIDATED STATEMENTS OF EARNINGS
                   (IN THOUSANDS, EXCEPT FOR PER SHARE DATA)
                                  (UNAUDITED)


<TABLE>
<CAPTION>


                                            Three months ended
                                               November 30,
                                          ----------------------

                                           1997          1998
                                          --------     ---------


<S>                                        <C>          <C>     
Net revenue                                $319,512     $447,941
  Cost of revenue                           278,167      397,366
                                           --------     --------

Gross profit                                 41,345       50,575

Operating expenses:
  Selling, general and administrative        11,077       18,318
  Research and development                      912        1,066
                                           --------     --------

Operating income                             29,356       31,191

  Interest expense, net                         713        1,520
                                           --------     --------

Income before income taxes                   28,643       29,671

  Income taxes                                9,572       10,385
                                           --------     --------

Net income                                 $ 19,071     $ 19,286
                                           ========     ========

Basic earnings per share                   $   0.52     $   0.52
                                           ========     ========

Diluted earnings per share                 $   0.49     $   0.50
                                           ========     ========

Common shares used in the calculations
of basic earnings per share                  37,019       37,283
                                           ========     ========

Common and common equivalent shares
used in the calculations of diluted
earnings per share                           38,675       38,827
                                           ========     ========


</TABLE>




       See Accompanying Notes to Consolidated Financial Statements






                                    4


<PAGE>   5
                      JABIL CIRCUIT, INC. AND SUBSIDIARIES
                     CONSOLIDATED STATEMENTS OF CASH FLOWS
                                 (IN THOUSANDS)
                                  (UNAUDITED)


<TABLE>
<CAPTION>


                                                         Three months ended
                                                            November 30,
                                                       ----------------------
                                                         1997          1998
                                                       -------      ---------
<S>                                                     <C>          <C>
Cash flows from operating activities:
  Net income                                           $ 19,071      $ 19,286
  Adjustments to reconcile net income to net cash
    provided by (used in) operating activities:
      Depreciation and amortization                       7,128        11,507
      Recognition of grant revenue                         (203)         (201)
      Deferred income taxes                                 706         1,895
      Loss on sale of property                               18           718
      Changes in operating assets and liabilities:
        Accounts receivable                             (17,370)      (54,517)
        Inventories                                     (15,592)      (23,175)
        Prepaid expenses and other current assets           (25)       (1,595)
        Other assets                                       (784)           32
        Accounts payable and accrued expenses            28,544        69,225
                                                       --------      --------

      Net cash provided by operating activities          21,493        23,175
                                                       --------      --------

Cash flows from investing activities:
  Acquisition of property, plant and equipment          (31,418)      (34,006)
  Proceeds from sale of property and equipment               10           172
                                                       --------      --------

      Net cash used in investing activities             (31,408)      (33,834)
                                                       --------      --------

Cash flows from financing activities:
  Increase in note payable to bank                       10,000            --
  Payments of long-term debt                             (2,475)           --
  Net proceeds from issuance of common stock                 84           141
  Proceeds from Scottish grant                               --           395
                                                       --------      --------

      Net cash provided by financing activities           7,609           536
                                                       --------      --------

Net decrease in cash                                     (2,306)      (10,123)
Cash at beginning of period                              45,457        23,139
                                                       --------      --------

Cash at end of period                                  $ 43,151      $ 13,016
                                                       ========      ========

</TABLE>




          See Accompanying Notes to Consolidated Financial Statements




                                       5



<PAGE>   6

                     JABIL CIRCUIT, INC. AND SUBSIDIARIES


                   NOTES TO CONSOLIDATED FINANCIAL STATEMENTS
                                  (UNAUDITED)


 NOTE 1.  SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES


     BASIS OF PRESENTATION

                  The accompanying consolidated financial statements of Jabil
         Circuit, Inc. and subsidiaries ("the Company") are unaudited and have
         been prepared based upon prescribed guidance of the Securities and
         Exchange Commission ("SEC"). As such, they do not include all
         disclosures required by generally accepted accounting principles, and
         should be read in conjunction with the annual audited consolidated
         statements as of and for the year ended August 31, 1998 contained in
         the Company's 1998 annual report on Form 10-K. In the opinion of
         management, the accompanying consolidated financial statements include
         all adjustments, consisting of normal and recurring adjustments
         necessary for a fair presentation of the financial position, results
         of operations and cash flows for the periods presented when read in
         conjunction with the annual audited consolidated financial statements
         and related notes thereto. The results of operations for the
         three-month period ended November 30, 1998 are not necessarily
         indicative of the results that should be expected for a full fiscal
         year.


     EARNINGS PER SHARE


                  The Company adopted Statement of Financial Accounting
         Standards No. 128 (SFAS 128), "Earnings per Share," in the second
         quarter of fiscal 1998. Under SFAS 128, the Company presents two
         earnings per share (EPS) amounts. Basic EPS is calculated based on net
         earnings available to common shareholders and the weighted-average
         number of shares outstanding during the reported period. Diluted EPS
         includes additional dilution from potential common stock, such as
         stock issuable pursuant to the exercise of stock options outstanding.
         All earnings per share amounts for all periods have been presented,
         and where necessary, restated to conform to the Statement 128
         requirements.






                                       6

<PAGE>   7


<TABLE>
<CAPTION>


           In thousands                                                       Three months ended
                                                                                 November 30,
                                                                            1997             1998
                                                                          -----------     ------------
<S>                                                                     <C>                <C> 
 Numerator:
 Net income                                                             $19,071               $19,286

 Denominator:
 Denominator for basic EPS-
 weighted-average shares                                                 37,019                37,283
 Effect of dilutive securities:
     Employee stock options                                               1,656                 1,544
                                                                        -------               -------
 Denominator for diluted EPS-adjusted
 weighted-average shares                                                 38,675                38,827
                                                                        =======               =======

 Basic EPS                                                              $  0.52               $  0.52
                                                                        =======               =======
 Diluted EPS                                                            $  0.49               $  0.50
                                                                        =======               =======

</TABLE>


                  For the three-month periods ended November 30, 1997 and 1998,
         options to purchase 20,000 and 40,000, respectively, shares of common
         stock were outstanding during the period but were not included in the
         computation of diluted earnings per share because the options'
         exercise prices were greater than the average market price of the
         common shares, and therefore, the effect would be antidilutive.


COMMITMENTS AND CONTINGENCIES

                  At November 30, 1998, the Company had approximately $40
         million in new facility and equipment purchase commitments
         outstanding.

                  The Company is party to certain lawsuits in the ordinary
         course of business. Management does not believe that these
         proceedings, individually or in aggregate, are material or that any
         adverse outcomes of these lawsuits will have a material adverse effect
         on the Company's financial statements.



NEW ACCOUNTING PRONOUNCEMENTS

                  Effective September 1, 1998, the Company adopted Statement of
         Financial Accounting Standards No. 130, Reporting Comprehensive
         Income. Statement 130 establishes standards for reporting
         comprehensive income. The Statement defines comprehensive income as
         the change in equity of an enterprise except those resulting from
         shareholder transactions. During the three months ended November 30,
         1998, changes in stockholders' equity consisted of net income and the
         exercise of stock 







                                       7


<PAGE>   8

        options. Accordingly, comprehensive income as defined by Statement
        130 was equal to net income as shown in the accompanying unaudited
        Consolidated Statement of Earnings.

                  In June 1997, the FASB issued Statement of Financial
         Accounting Standards No. 131, Disclosures About Segments of an
         Enterprise and Related Information. Statement 131 establishes
         standards for related disclosures about the products and services,
         geographic areas, and major customers of an enterprise. The Company
         will be required to adopt this Statement in its 1999 annual
         consolidated financial statements. As this Statement addresses
         reporting and disclosure issues only, there will be no impact on
         earnings from its adoption.

                  Statement 133 - Accounting for Derivative Instruments and
         Hedging Activities. Statement 133 establishes methods of accounting
         for derivative financial instruments and hedging activities related to
         those instruments as well as other hedging activities. The Company is
         currently evaluating this Statement and has yet to form an opinion on
         whether its adoption will have any significant impact on the Company's
         consolidated financial statements. The Company will be required to
         implement Statement 133 for its fiscal year ending August 31, 2000.

                  Statement of Position 98-5 Reporting on the Costs of Start Up
         Activities. SOP 98-5 establishes standards on the financial reporting
         of start-up costs and organization costs. SOP 98-5 requires costs of
         start-up activities and organization costs to be expensed as incurred.
         The SOP is effective for financial statements for fiscal years
         beginning after December 15, 1998. As the Company has historically
         made a practice of expensing costs related to both the establishment
         of greenfield manufacturing facilities and the set-up of production
         lines as such costs are incurred, it does not anticipate that the
         adoption of SOP 98-5 will have any material impact on its consolidated
         financial statements.


 NOTE 2.  BALANCE SHEET DETAIL

                  The components of inventories consist of the following:

<TABLE>
<CAPTION>

                    In thousands                             August 31,         November 30,
                                                                   1998                 1998
                                                              ---------         ------------ 
                                                                                 (Unaudited)

                    <S>                                       <C>                <C>  
                    Finished goods                                5,823                2,799
                    Work-in-process                              15,955               12,748
                    Raw materials                               101,319              130,725
                                                                -------              -------
                                                                123,097              146,272
                                                                =======              =======

</TABLE>


                                       8

<PAGE>   9


                      JABIL CIRCUIT, INC. AND SUBSIDIARIES

         This Management's Discussion and Analysis of Financial Condition and
Results of Operations contains certain forward-looking statements within the
meaning of that term in Section 27A of the Securities Act of 1933, as amended,
and Section 21E of the Securities Exchange Act of 1934, as amended. Factors
that could cause actual events or results to differ materially from those
referenced in such forward-looking statements include those described in the
section herein entitled "Factors Affecting Future Results" and in the Company's
other filings with the Securities and Exchange Commission. The words "believe,"
"expect," "intend," "anticipate," "plan" and similar expressions and variations
thereof identify certain of such forward-looking statements, which speak only
as of the dates on which they are made. The Company undertakes no obligation to
publicly update or revise any forward-looking statements, whether as a result
of new information, future events or otherwise. Readers are cautioned that any
such forward-looking statements are not guarantees of future performance and
involve risks and uncertainties, and that actual events and results may differ
materially from those indicated in the forward-looking statements as a result
of various factors. Readers are cautioned not to place undue reliance on any
forward-looking statements.


I
tem 2. MANAGEMENT'S DISCUSSION AND ANALYSIS OF FINANCIAL CONDITION AND RESULTS
        OF OPERATIONS

         The Company's net revenue for the first quarter of fiscal 1999
increased 40% to $448 million from $320 million in the first quarter of fiscal
1998. This increase from the previous fiscal year was primarily due to
increased production of communications products as well as incremental revenue
due to the recent HP acquisition. Foreign source revenue represented 32% of net
revenue for the first quarter of fiscal 1999 compared to 34% for the same
period of fiscal 1998. The decrease in foreign source revenue was attributable
to increased production at the Company's domestic locations in addition to the
incremental revenue due to the recent acquisition of certain manufacturing and
related assets comprising the "Formatter Manufacturing Organization" business
unit of Hewlett-Packard Company ("HP acquisition").

         Gross margin decreased to 11.3% for the first quarter of fiscal 1999
from 12.9% for the same period of fiscal 1998 reflecting a higher content of
material-based revenue from the HP acquisition, underutilization of assets in
certain international factories, offset in part by the recovery of costs
associated with defective materials from a supplier.

         Selling, general and administrative expenses in the first quarter of
fiscal 1999 increased to 4.1% of net revenue compared to 3.5% in the prior
fiscal year, while increasing in absolute dollars from $11.1 million in the
first quarter of fiscal 1998 to $18.3 million in the first quarter of fiscal
1999. The dollar increases were primarily due to increased staffing and related
departmental expenses at all the Company's locations, increased information
systems staff to support the expansion of the Company's business, and staffing
at the acquired HP sites.

         Research and development expenses decreased to 0.2% of net revenue for
the first quarter of fiscal 1999 as compared to 0.3% for the same period of
fiscal 1998. In absolute dollars, the expenses increased approximately $0.2
million versus the same period of fiscal 1998 due to the expansion of circuit
design activities.






                                       9
 

<PAGE>   10

        Interest expense increased approximately $0.8 million in the first
quarter of fiscal 1999 to $1.5 million as a result of increased borrowings to
support the HP acquisition and increase working capital requirements.

         The Company's effective tax rate increased to 35.0% in the first
quarter of fiscal 1999 from 33.4% in the first quarter of fiscal 1998. The
fiscal 1999 tax rate is higher primarily due to increased levels of domestic
income as compared to the same period of fiscal 1998.

BUSINESS FACTORS

         Due to the nature of turnkey manufacturing and the Company's
relatively small number of customers, the Company's quarterly operating results
are affected by the level and timing of orders, the level of capacity
utilization of its manufacturing facilities and associated fixed costs,
fluctuations in material costs, and by the mix of material costs versus
manufacturing costs. Similarly, operating results are affected by price
competition, level of experience in manufacturing a particular product, degree
of automation used in the assembly process, efficiencies achieved by the
Company in managing inventories and fixed assets, timing of expenditures in
anticipation of increased sales, customer product delivery requirements, and
shortages of components or labor. In the past, some of the Company's customers
have terminated their manufacturing arrangement with the Company, and other
customers have significantly reduced or delayed the volume of manufacturing
services ordered from the Company. Any such termination of a manufacturing
relationship or change, reduction or delay in orders could have an adverse
affect on the Company's results of operations.

LIQUIDITY AND CAPITAL RESOURCES 

         At November 30, 1998, the Company's principal sources of liquidity
consisted of cash and available borrowings under the Company's credit
facilities. The Company and its subsidiaries have committed line of credit
facilities in place with a syndicate of banks that provide up to $225 million
of working capital borrowing capacity. As of November 30, 1998, the Company was
utilizing $40 million of its revolving credit facility.

           The Company generated $23.2 million of cash in operating activities
for the three months ended November 30, 1998. The generation of cash was
primarily due to net income of $19.3 million, depreciation and amortization of
$11.5 million, an increase of $54.5 million in accounts receivable, an increase
in inventories of $23.2 million and an increase in accounts payable and accrued
expenses of $69.2 million.

         Net cash used in investing activities of $33.8 million for the three
months ended November 30, 1998 was a result of the Company's capital
expenditures for equipment worldwide in order to support increased activities.

         The Company believes that cash on-hand, funds provided by operations
and available borrowings under the credit facility will be sufficient to
satisfy its currently anticipated working capital and capital expenditure
requirements for the next twelve months.




                                      10

<PAGE>   11

"YEAR 2000" READINESS

         The Company is aware of and is addressing the Year 2000 issue. The
Year 2000 issue creates risks for the Company from unforeseen problems in its
own computer systems and from third parties with whom the Company deals.
Failure of the Company's and/or third parties computer systems, manufacturing
equipment and control systems could have a material adverse effect on the
Company's results from operations.

          The Company is actively taking steps to ensure that its global
information technology infrastructure and business system applications,
manufacturing equipment and systems will be Year 2000 compliant while seeking
adequate assurances from third parties with whom the Company conducts business
with, that any such systems shall be Year 2000 compliant. A global team,
overseen by a corporate officer, has been formed and has implemented a
proactive multi-phase approach, which includes assessing the scope of work,
prioritizing, certifying compliance, and testing compliance.

          As of the end of fiscal 1998 the Company was substantially complete
in its compliance certification process of its global information technology
infrastructure. Most of the Company's global business systems are currently
being replaced by a Year 2000 compliant application; this process is expected
to be complete by January 1, 2000. As a contingency, however, legacy systems
have been upgraded to be Year 2000 compliant and are in the process of being
tested.

          As of the end of fiscal 1998, manufacturing and test equipment and
local plant business systems had been identified and prioritized in terms of
Year 2000 compliance. As of November 30, 1998, 85% of all equipment and systems
had been certified as compliant. It is anticipated that the remaining 15% will
be certified by the end of the first calendar quarter of 1999, at which time
compliance testing and verification will commence.

          The Company is also in the process of assessing its suppliers. The
initial phase of the assessment has been completed as of the end of calendar
1998. Early in calendar 1999, the Company anticipates validating its suppliers'
representations where deemed appropriate, and will develop sourcing contingency
plans in areas where the Company assesses that supplier readiness is
insufficient.

          The Company estimates the cost to complete its remediation to be
approximately $3 million. The Company is unable to fully determine the effect
of failure of its own systems or those of third parties with which it does
business, but any significant failures could have an material adverse effect on
the Company's financial position, results of operations and cash flows.



                                      11

<PAGE>   12


                      JABIL CIRCUIT, INC. AND SUBSIDIARIES



P
art II - OTHER INFORMATION



         ITEM 6:        EXHIBITS AND REPORTS ON FORM 8-K

                        (a)     Exhibits

                                27.  Financial Data Schedule.

                        (b)     Reports on Form 8-K

                                There were no reports on Form 8-K filed by the 
                                Registrant during the quarter ended 
                                November 30, 1998.







                                   SIGNATURES



Pursuant to the requirements of the Securities and Exchange Act of 1934, the
registrant has duly caused this report to be signed on its behalf by the
undersigned, thereunto duly authorized.


                                       Jabil Circuit, Inc.
                                       Registrant

Date: January 14, 1999                           By:      /s/ Thomas A. Sansone
      ----------------                                    ---------------------
                                                 Thomas A. Sansone
                                                 President

Date: January 14, 1999                           By:     /s/ Chris A. Lewis
      ----------------                                    ------------------
                                                 Chris A. Lewis
                                                 Chief Financial Officer





                                      12





<TABLE> <S> <C>

<ARTICLE> 5
<LEGEND>
THIS SCHEDULE CONTAINS SUMMARY FINANCIAL INFORMATION EXTRACTED FROM THE
CONSOLIDATED BALANCE SHEET AND THE CONSOLIDATED STATEMENT OF INCOME FILED AS
PART OF THE QUARTERLY REPORT ON FORM 10-Q AND IS QUALIFIED IN ITS ENTIRETY BY
REFERENCE TO SUCH FINANCIAL STATEMENTS
</LEGEND>
<MULTIPLIER> 1,000
       
<S>                             <C>
<PERIOD-TYPE>                   3-MOS
<FISCAL-YEAR-END>                          AUG-31-1999
<PERIOD-END>                               NOV-30-1998
<CASH>                                          13,016
<SECURITIES>                                         0
<RECEIVABLES>                                  184,069
<ALLOWANCES>                                     3,276
<INVENTORY>                                    146,272
<CURRENT-ASSETS>                               358,408
<PP&E>                                         350,904
<DEPRECIATION>                                 104,408
<TOTAL-ASSETS>                                 616,309
<CURRENT-LIABILITIES>                          255,944
<BONDS>                                              0
<PREFERRED-MANDATORY>                                0
<PREFERRED>                                          0
<COMMON>                                            37
<OTHER-SE>                                     267,756
<TOTAL-LIABILITY-AND-EQUITY>                   616,309
<SALES>                                        447,941
<TOTAL-REVENUES>                               447,941
<CGS>                                          397,366
<TOTAL-COSTS>                                  416,750
<OTHER-EXPENSES>                                     0
<LOSS-PROVISION>                                     0
<INTEREST-EXPENSE>                               1,520
<INCOME-PRETAX>                                 29,671
<INCOME-TAX>                                    10,385
<INCOME-CONTINUING>                             19,286
<DISCONTINUED>                                       0
<EXTRAORDINARY>                                      0
<CHANGES>                                            0
<NET-INCOME>                                    19,286
<EPS-PRIMARY>                                     0.52
<EPS-DILUTED>                                     0.50
        

</TABLE>