William Patrick "Parry" O'Brien (January 28, 1932 – April 21, 2007) was an American shot put champion.

He won the (non-standard for high schoolers) 16-pound shot put competition at the 1949 CIF California State Meet.

[4] O'Brien enrolled in college at U.S.C., where he continued to play football as a freshman until he was kicked in the stomach during practice and injured.

[5] During his career he won 18 Amateur Athletic Union championships (combined outdoor and indoor), 17 in the shot put, plus one in the discus.

As a competitor, in addition to developing new techniques for the shot put, he also made motivational tapes for himself, and experimented with yoga.

Time magazine, in a cover story[6] written during the week before the 1956 Summer Olympics, noted "None has been more successful than O'Brien in combining what he calls 'M.A.'

[5] After retiring from senior competitions, O'Brien worked in the banking and real estate business in Southern California.