Charles Siebert (চার্লস সিবার্ট) was an American actor and television director. As an actor, he is 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, and for his numerous appearances on the $25,000 Pyramid. 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.

One of acting's more reliable performers from the 1970s through the early 1990s, Charles Siebert alternated between the live theater and film/television as both an actor and director. Born the eldest of four children in 1938 in Wisconsin, he started his career following journalism school at Marquette University and a stint in the U.S. Army in the 60s. After marrying his college sweetheart, Catherine Kilzer, he trained at the London Academy of Music and Dramatic Arts. They eventually returned to the United States with their English-born son, Christopher, and resided in New York City where two more children, Charles Andrew and Gillian, were born.

Following work in various regional theatre productions, Charles graduated to roles on the Broadway and off-Broadway stages. He made his Broadway debut in Galileo (1967) and appeared in such other New York plays as "The Gingerbread Lady" (1970) with Tony winner Maureen Stapleton, "Sticks and Bones" (1972), and the 1974 revival of "Cat on a Hot Tin Roof" starring Elizabeth Ashley in which he played the role of Gooper. He was also in the cast of the 1968 musical "Jimmy Shine" starring Dustin Hoffman. Simultaneously, Charles was appearing in such New York-based daytime soaps as "Search for Tomorrow," "Another World," and "As the World Turns."