Sheffield portrayed swimming champion-turned-movie star Johnny Weissmuller and Maureen O'Sullivan's orphaned child, Boy, in films like Tarzan Finds A Son! and Tarzan & The Amazons.
He died at his home in Chula Vista, California on Friday (15Oct10) after suffering a heart attack, according to the Los Angeles Times.
His wife Patty tells the publication he fell from a ladder while pruning a palm tree.
The son of British actor Reginald Sheffield was seven when he first auditioned as Boy and beat 300 other kids to land the role of Weissmuller's son, rescued from a jungle plane wreck in which his biological parents are killed.
Sheffield had to take swimming lessons from Olympian Weissmuller after studio bosses learned the youngster couldn't swim.
He played Boy in eight Tarzan films between 1939 and 1947, and later starred in the Bomba, the Jungle Boy film series.
Sheffield went on to earn a business degree and worked in farming, construction and real estate.