Tarzan Finds a Son! is a 1939 Tarzan film based on the character created by Edgar Rice Burroughs. It was the fourth in the MGM Tarzan series to feature Johnny Weissmuller as the "King of the Apes" and the fourth of six films in which he stars with Maureen O'Sullivan as Jane; following this pairing was Tarzan's Secret Treasure (1941) and Tarzan's New York Adventure (1942).

Johnny Weissmuller was an American Olympic swimmer, water polo player and actor. He was known for having one of the best competitive swimming records of the 20th century. He set world records alongside winning five gold medals in the Olympics. He won the 100m freestyle and the 4 × 200 m relay team event in the 1924 Summer Olympics in Paris and the 1928 Summer Olympics in Amsterdam. Weissmuller also won gold in the 400m freestyle, as well as a bronze medal in the water polo competition in Paris.