(written from a Production point of view)
Besides his stint on Star Trek, Brian has also made guest appearances in many other television series, including The Untouchables, I Dream of Jeannie, Rawhide, Gunsmoke, and Mission: Impossible. He also starred in his own series, Mr. District Attorney, from 1954 through 1955.
Throughout the early 1950s, Brian was often seen playing the lead role in films such as Breakthrough (1950, co-starring William Campbell and Ricardo Montalban) and Inside Straight (1951, with John Hoyt). His other film credits include supporting roles in 1952's Springfield Rifle (with Richard Hale) and This Woman Is Dangerous (with Richard Webb), 1954's The High and the Mighty (with William Campbell, Paul Fix, and William Schallert), 1961's Pocketful of Miracles (featuring Grace Lee Whitney), the classic 1962 western How the West Was Won, 1966's The Rare Breed (with Brian Keith), 1968's The Destructors (with Michael Ansara), and 1969's The Girl Who Knew Too Much (with Nehemiah Persoff). His last feature film appearance was in 1971's The Seven Minutes, which also featured fellow TOS co-stars Stanley Adams and Charles Napier. He would, however, co-star with Madlyn Rhue the following year in The Manhunter, a made-for-TV movie.