Jacques Joseph O'Mahoney (February 7, 1919 – December 14, 1989), known professionally as Jock Mahoney, was an American actor and stuntman. He starred in two Western television series, The Range Rider and Yancy Derringer. He played Tarzan in two feature films and was associated in various capacities with several other Tarzan productions. He was sometimes credited as Jack O'Mahoney or Jock O'Mahoney. According to step-daughter Sally Field, he was a child molester (see Personal section).