Johnny Weissmuller
34 movie credits (many playing Tarzan), 2 shorts, and 26 episodes of the Jungle Jim television series for this winner of five Olympic Gold Medals.
Discuss here: http://www.imdb.com/board/bd0000088/flat/247253385
Note 1: A career as a sports announcer, a reality show star, or a show host does not count as an acting career.
Note 2: Sonja Henie has only 14 acting credits. Bruce Jenner also has 14. Mary Lou Retton and Mark Spitz have 4 each.