Filed Pursuant to Rule 424(b)(3) and (c)
File Number 333-47590

PROSPECTUS SUPPLEMENT DATED DECEMBER 12, 2000
to
Prospectus Dated October 19, 2000

ADC TELECOMMUNICATIONS, INC.

38,486,766 Shares
of
Common Stock
($.20 Par Value)

    This Prospectus Supplement supplements the Prospectus dated October 19, 2000 (the "Prospectus") of ADC Telecommunications, Inc., a Minnesota corporation (the "Company"), relating to an aggregate of 38,486,766 shares of Common Stock, par value $.20 per share (the "Common Stock"), of the Company that may be sold from time to time by certain shareholders of the Company who received such shares in connection with the Company's acquisition of Broadband Access Systems, Inc., or by donees, pledgees, transferees or other successors-in-interest that receive such shares as a gift, pledge, distribution to members or partners or other non-sale-related transfer (the "Selling Shareholders"). This Prospectus Supplement should be read in conjunction with, and is qualified by reference to, the Prospectus except to the extent that the information herein contained supersedes the information contained in the Prospectus. Capitalized terms used in this Prospectus Supplement and not otherwise defined herein have the meanings specified in the Prospectus.

SELLING SHAREHOLDERS

    Recently Norwest Venture Partners VII, L.P. distributed 4,485,356 shares of ADC Common Stock to the partners of such fund, including Itasca VC Partners VII, LLP, which immediately thereafter distributed the shares it received to its partners. PH Ventures VII, LLC distributed 1,886,275 shares of ADC Common Stock to the partners of such fund. Still River Fund, L.P. distributed 3,157,819 shares of ADC Common Stock to the partners of such fund, including Joseph J. Tischler, who gifted 800 shares to New Jewish High School and 2,400 shares to Combined Jewish High School. Matrix Partners V, L.P. may distribute 13,255,264 shares of ADC Common Stock to the partners of such fund. Pirjo Tuomi transferred 310,286 shares of ADC Common Stock to the Pirjo T. Tuomi 1999 Family Trust dtd 9/17/99, and Paul E. Nikolich transferred 400,000 shares of ADC Common Stock to Paul E. Nikolich and Laura L. Nikolich, Trustees of The Nikolich Family GRAT. Additionally, North Bridge Venture Partners II, L.P., North Bridge Venture Partners IV-A, L.P. and North Bridge Venture Partners IV-B, L.P., may distribute up to 7,956,528 shares of ADC Common Stock to the partners of such funds. Except as otherwise noted below, none of such transferees were specifically named in the Prospectus. The following table lists the Selling Shareholders not previously specifically identified in the Prospectus as a selling shareholder, and the number of shares each such Selling Shareholder beneficially owns and may sell, as well as updates the number of shares beneficially owned and available for sale by the Selling Shareholders noted below who were previously listed as a selling shareholder, pursuant to the

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Prospectus from time to time. The table of Selling Shareholders in the Prospectus is hereby amended to include the persons or entities identified below as Selling Shareholders:

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(1)

The registration statement to which the Prospectus and this Prospectus Supplement relate shall also cover any additional shares of Common Stock which become issuable in connection with the shares registered for sale hereby by reason of any stock dividend, stock split, recapitalization or other similar transaction effected without the receipt of consideration which results in an increase in the number of the Company's outstanding shares of Common Stock.

(2)

Except as otherwise indicted, represents less than 1% of the outstanding shares as of the date of this Prospectus Supplement. Information about the beneficial ownership of our shares has been given to us by the selling shareholders. The inclusion of any shares in this table does not constitute an admission of beneficial ownership for the name selling shareholders.

(3)

Assumes the sale of all shares offered by the Prospectus and this Prospectus Supplement.

(4)

Previously listed as a Selling Shareholder in the Prospectus dated October 19, 2000.

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