James X. Mitchell's acting career began with his notable role as Lt. Josephs in the Star Trek: The Original Series second season episode "Journey to Babel", which was filmed on Friday, September 22, 1967, at Desilu Stage 9.
Prior to this, Mitchell had signed a contract with Paramount and joined the cast of the film Rogue's Gallery in September 1967, alongside Lee Delano, Chuck Hicks, Bob Hoy, and William Meader. He also appeared in Buckskin in December of the same year, alongside Nick Borgani. After these roles, Mitchell seemingly retired from professional acting.
However, Mitchell did not completely leave the entertainment industry. In 2003, he was living in Paris, France, where he pursued a career as a screenwriter and translator. He translated the nonfiction title Who Killed Daniel Pearl-Levy?, and continued to work in the industry.
In 2010, Mitchell was still residing in Paris, where he represented the global organization known as "Americans Against the War", showcasing his dedication to social and political causes.
