Richard Timothy Smith (born 25 March 1942), known professionally as Richard O'Brien, is an English-New Zealand actor, writer, composer, and television presenter. He wrote the musical stage show The Rocky Horror Show in 1973, which has remained in almost continuous production. He also co-wrote the screenplay of the film adaptation, The Rocky Horror Picture Show (1975), appearing in the film as Riff Raff. The film became an international success and has received a large cult following. O'Brien wrote Shock Treatment (1981) and appeared in the film as Dr. Cosmo McKinley.
O'Brien presented four series of the Channel 4 game show The Crystal Maze (1990–1993, 2016). He played the voice role of Lawrence Fletcher in the Disney Channel animated series Phineas and Ferb (2007–2015) and its two films (2011 and 2020). O'Brien has also appeared in films including Dark City (1998), Ever After (1998), Dungeons & Dragons (2000), Elvira's Haunted Hills (2001), and Jackboots on Whitehall (2010).
After a long and successful career based in the United Kingdom, O'Brien gained dual citizenship with New Zealand in 2011, where he resided in Tauranga. He identifies as third sex and uses he/him pronouns.