Mark Francis O'Meara (born January 13, 1957) is an American professional golfer who was a prolific tournament winner on the PGA Tour and around the world from the mid 1980s to the late 1990s. He spent nearly 200 weeks in the top-10 of the Official World Golf Rankings from their debut in 1986 to 2000.
O'Meara was born in Goldsboro, North Carolina, but grew up in southern California in Mission Viejo. He took up golf at age 13, sneaking on to the nearby Mission Viejo Country Club. O'Meara later became an employee of the club and played on his high school golf team. He was an All-American at Long Beach State, and won the U.S. Amateur in 1979, defeating John Cook. After graduating with a degree in marketing in 1980, O'Meara turned professional and would win 16 events on the PGA Tour, beginning with the Greater Milwaukee Open in 1984. He won the AT&T Pebble Beach National Pro-Am five times, but he passed his 41st birthday in January 1998 without having won a major championship as a professional.
In a late finale to his PGA Tour winning career, O'Meara won two majors in 1998, The Masters and the British Open. O'Meara attributed this resurgence partly to the inspiration of working with Tiger Woods, the new superstar of the game at the time, with whom O'Meara had become good friends. In the same year he won the Cisco World Match Play Championship and he reached a career best of second in the Official World Golf Rankings.