Walter Charles Hagen (December 21, 1892 – October 6, 1969) was an American professional golfer and a major figure in golf in the first half of the 20th century. His tally of 11 professional majors is third behind Jack Nicklaus (18) and Tiger Woods (15). Known as the "father of professional golf," he brought publicity, prestige, big prize money, and lucrative endorsements to the sport. Hagen is rated one of the greatest golfers ever.

Hagen won the U.S. Open twice, and in 1922 he became the first native-born American to win The Open Championship, and won the Claret Jug three more times. He also won the PGA Championship a record-tying five times (all in match play), and the Western Open five times when it had near-major championship status. Hagen totaled 45 PGA wins in his career, and was a six-time Ryder Cup captain.