Richard Simmons was an American actor. He played a number of minor parts in MGM movies but finally achieved a degree of fame in the mid-1950s when he starred in the half-hour syndicated TV series, Sergeant Preston of the Yukon (1955). Richard Simmons was an American actor. He played a number of minor parts in MGM movies but finally achieved a degree of fame in the mid-1950s when he starred in the half-hour syndicated TV series, Sergeant Preston of the Yukon (1955).