William Warden Kerr[1] (September 9, 1847 – February 18, 1917)[2] was an American business executive in wholesale grocery, best remembered as controlling owner of the Pittsburgh Pirates professional baseball team of the National League (NL) from 1893 through 1900 with Phil Auten.

[3] In early 1893, the two men gained a controlling interest in Pittsburgh's National League club, the Pirates, which had absorbed and merged ownership with the defunct Players' League club, when they and manager Al Buckenberger bought out the stock of William Chase Temple.

[4] Kerr and Auten sold their majority share of the Pirates to Barney Dreyfuss prior to the 1901 season.

Kerr's father, also named William, was a physician and the 14th Mayor of Pittsburgh; his mother was from Philadelphia.

[1] Kerr began his business career with Standard Oil in Philadelphia, until taking a position with Arbuckles & Co., a coffee and grocery wholesaler, in Pittsburgh in 1876.