1
 
                                             This filing is made pursuant
                                             to Rule 424(b)(3) under the
                                             Securities Act of 1933 in
                                             connection with Registration
                                             No. 333-58857
PROSPECTUS SUPPLEMENT NO. 15 TO
PROSPECTUS DATED JULY 23, 1998
 
                               INGRAM MICRO INC.
                 $1,330,000,000 PRINCIPAL AMOUNT AT MATURITY OF
               ZERO COUPON CONVERTIBLE SENIOR DEBENTURES DUE 2018
                                      AND
                              CLASS A COMMON STOCK
                        ISSUABLE UPON CONVERSION THEREOF
 
     This Prospectus Supplement relates to the resale by the holders listed
below of Zero Coupon Convertible Senior Debentures due 2018 of Ingram Micro Inc.
and the shares of Class A Common Stock ("Common Stock") of the Company issuable
upon the conversion of the Debentures (the "Conversion Shares").
 
     You should read this Prospectus Supplement together with the Prospectus
dated July 23, 1998, which is to be delivered with this Prospectus Supplement.
All capitalized terms used but not defined in this Prospectus Supplement shall
have the meanings given them in the Prospectus.
 
     The table below sets forth information as of the date hereof concerning
beneficial ownership of the Debentures and Common Stock by the selling
securityholders listed. All information concerning beneficial ownership has been
furnished by the selling securityholders.


                             PRINCIPAL
                             AMOUNT OF                        NUMBER          OTHER       PERCENTAGE OF      PERCENTAGE OF
                            DEBENTURES    PERCENTAGE OF   OF CONVERSION     SHARES OF         COMMON            COMMON
                               THAT        DEBENTURES      SHARES THAT     COMMON STOCK       STOCK             EQUITY
           NAME             MAY BE SOLD    OUTSTANDING    MAY BE SOLD(1)       HELD       OUTSTANDING(2)   OUTSTANDING(2)(3)
           ----             -----------   -------------   --------------   ------------   --------------   -----------------
                                                                                         
The Northwestern Mutual
  Life Insurance
  Company.................  $9,000,000           *            49,455            0               *                  *
 

 
                            PERCENTAGE OF VOTING
                                  POWER OF
                               COMMON EQUITY
           NAME             OUTSTANDING(2)(3)(4)
           ----             --------------------
                         
The Northwestern Mutual
  Life Insurance
  Company.................           *

 
- ---------------
 
 *  Less than 1%.
 
(1) Assumes conversion of the full amount of Debentures held by such holder at
    the initial conversion rate of 5.495 shares of Common Stock per $1,000
    principal amount at maturity of Debentures; this conversion rate is subject
    to adjustment as described under "Description of Debentures -- Conversion of
    Debentures." Accordingly, the number of shares of Common Stock issuable upon
    conversion of the Debentures may increase or decrease from time to time.
    Under the terms of the Indenture, we will not issue fractional shares upon
    conversion of the Debentures; we will pay cash in lieu of fractional shares,
    if any.
 
(2) Computed in accordance with Rule 13d-3(d)(i) promulgated under the Exchange
    Act and based upon 143,054,969 shares of Common Stock outstanding as of
    March 16, 1999, treating as outstanding the number of Conversion Shares
    shown as being issuable upon the assumed conversion by the named holder of
    the full amount of such holder's Debentures but not assuming the conversion
    of the Debentures of any other holder.
 
(3) Based upon 74,722,166 shares of Class B Common Stock outstanding as of March
    16, 1999. See "Description of Capital Stock" in the Prospectus.
 
(4) Each share of Common Stock entitles the holder to one vote on each matter
    submitted to a vote of the Company's shareowners and each share of Class B
    Common Stock entitles the holder to ten votes on each such matter. See
    "Description of Capital Stock -- Common Equity -- Voting Rights" in the
    Prospectus.
 
                            ------------------------
 
     YOU SHOULD CAREFULLY CONSIDER THE MATTERS DISCUSSED UNDER THE CAPTION "RISK
FACTORS" STARTING ON PAGE 6 OF THE PROSPECTUS.
                            ------------------------
 
     NEITHER THE SECURITIES AND EXCHANGE COMMISSION NOR ANY STATE SECURITIES
COMMISSION HAS APPROVED OR DISAPPROVED OF THESE SECURITIES OR DETERMINED IF THIS
PROSPECTUS IS TRUTHFUL OR COMPLETE. ANY REPRESENTATION TO THE CONTRARY IS A
CRIMINAL OFFENSE.
                            ------------------------
 
            THE DATE OF THIS PROSPECTUS SUPPLEMENT IS MAY 13, 1999.