Peter Joseph O'Hara (August 21, 1885 – April 11, 1977) was an Irish-American professional golfer who played in the early-to-mid 20th century. His best major championship finishes were a fifth place tie in the 1920 PGA Championship, a T7 finish in the 1924 U.S. Open, and a T8 result in the 1929 U.S. Open. He won the 1921 New Jersey Open and was a joint winner (with George Bowden) of the 1922 Houston Professional Golf tournament. O'Hara won the 1931 Western Pennsylvania Open Championship as well as the 1934 Bedford Open.