<Page> Exhibit 23.1 CONSENT OF INDEPENDENT ACCOUNTANTS We hereby consent to the incorporation by reference in the Registration Statement on Forms S-3 (File No. 333-71561, File No. 333-105523, File No. 333-74558, and File No. 333-62180) and S-8 (File No. 333-72967, File No. 333-84485, and File No. 333-100628) of Affiliated Managers Group, Inc. of our reports dated March 10, 2004 relating to the financial statements and financial statement schedule, which appear in this Form 10-K. /s/ PricewaterhouseCoopers LLP Boston, Massachusetts March 10, 2004