EXHIBIT 32.1

                           CERTIFICATION PURSUANT TO
                            18 U.S.C. SECTION 1350,
                       AS ADOPTED PURSUANT TO SECTION 906
                       OF THE SARBANES-OXLEY ACT OF 2002

     In connection with the Annual Report of Jabil Circuit, Inc. (the "Company")
on Form 10-K for the fiscal year ended August 31, 2003 as filed with the
Securities and Exchange Commission on the date hereof (the "Form 10-K"), I,
Timothy L. Main, President and Chief Executive Officer of the Company, hereby
certify, pursuant to 18 U.S.C. Section 1350, as adopted pursuant to Section 906
of the Sarbanes-Oxley Act of 2002, that:

          (1) The Form 10-K fully complies with the requirements of Section
     13(a) or 15(d) of the Securities Exchange Act of 1934 (15 U.S.C. 78m or
     78o(d)); and

          (2) The information contained in the Form 10-K fairly presents, in all
     material respects, the financial condition and results of operations of the
     Company.

Date: November 12, 2003

                                                  /s/ TIMOTHY L. MAIN
                                          --------------------------------------
                                                     Timothy L. Main
                                          President and Chief Executive Officer