Charles Alan Siebert was an American actor and television director. As an actor, he is probably best known for his role as Dr. Stanley Riverside II on the television series Trapper John, M.D., a role he portrayed from 1979 to 1986. After 1986, although he continued working as an actor, Siebert's career was focused on working as a director for episodic television for such shows as Xena: Warrior Princess, and Hercules: The Legendary Journeys.