<PAGE>
Prospectus Supplement filed under Rule 424(b)(3)
Registration No. 333-73301
Prospectus Supplement
The Prospectus dated July 1, 1999, relating to the offering for
resale of 1,201,154 shares of Common Stock of True North Communications Inc., a
form of which was filed with the Securities and Exchange Commission on July 9,
1999, and which was supplemented on July 16, 1999 (the "July 16 Supplement") is
hereby supplemented to amend and include the following information in the
"Selling Stockholders" table:
<TABLE>
<CAPTION>
Number of Shares to be
Beneficially Owned
Number of Shares After Offering,
Name of Selling Beneficially Owned Maximum Number of Assuming All Shares
Stockholder Prior to the Offering Shares to be Offered Offered are Distributed
- ---------------------- --------------------- --------------------- -----------------------
<S> <C> <C> <C>
Theodore H. Pincus 0/1/ 531,087 0
Trustee of the Theodore
H. Pincus Declaration of
Trust Dated 6/10/92
Georgica Partners 111,200/1/ 74,600 111,200/2/
Ralco Inc. 2,300/1/ 1,500 2,300/2/
Geo-Valor Ltd. 4,600/1/ 3,100 4,600/2/
Brown University 15,200/1/ 10,200 15,200/2/
The Georgica 9,600/1/ 6,400 9,600/2/
International Fund
Limited
Oak Foundation USA 6,300/1/ 4,200 6,300/2/
Inc.
</TABLE>
This Prospectus Supplement is dated July 22, 1999.
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/1/ Subsequent to the commencement of the Offering, Theodore H. Pincus,
Trustee of the Theodore H. Pincus Declaration of Trust Dated 6/10/92 transferred
100,000 of the 631,087 shares held by the Trust as provided in the July 16
Supplement to each of the other Selling Stockholders listed above in the
respective amounts listed in the column captioned "Maximum Number of Shares to
be Offered" opposite each such Selling Stockholder's name.
/2/ Assumes that there are not any sales by the Selling Stockholders of
the shares of True North common stock beneficially owned by them prior to the
commencement of the Offering.
