William Hoover Yawkey (August 22, 1875 – March 5, 1919 in Augusta, Georgia) was the sole owner of the Detroit Tigers of the American League from 1903 through 1908, and part-owner with Frank Navin from 1908 to 1919.
Yawkey was the son of lumber tycoon William Clyman Yawkey, the richest man in Michigan. The elder Yawkey agreed to buy the Tigers from Samuel F. Angus in 1903, but died before the deal closed. Navin, then the Tigers' bookkeeper and vice president, persuaded the younger Yawkey to complete the deal.
Yawkey took little interest in the Tigers, leaving day-to-day control in Navin's hands. In 1908, Yawkey sold almost half of the club's stock to Navin, making him for all intents and purposes a full partner.
Yawkey died in 1919 from the Spanish flu. Upon his death, he left his $40 million estate to his nephew and adoptive son, Tom Yawkey, who later bought the Boston Red Sox.