Derek Partridge (born 29 June 1935; age 89) is the British actor who played Dionyd in the Star Trek: The Original Series third season episode "Plato's Stepchildren". He filmed his scenes on Monday 9 September 1968, Tuesday 10 September 1968 and Tuesday 17 September 1968 at Desilu Stage 10.
Partridge's father was a diplomat in the British Foreign Service. He was 8 years old, when, in June 1943, he and his nanny gave up their seats to movie star Leslie Howard on a flight from Lisboa, Portugal to Bristol, England, which was subsequently shot down by the German air force, killing everyone on board, including Howard.
Partridge attended university in Paris and Barcelona and served in the Royal Air Force and as a City of London Special Constable before moving to acting. In the 1960s, he appeared on several British television series, including Dixon of Dock Green, Espionage, The Edgar Wallace Mystery Theatre, and Crossroads, as well as in an uncredited role in Thunderball (1965). He also played small roles in The Murder Game (1965), Where the Spies Are (1966) and The Killing of Sister George (1968).
In the 1970s, Partridge moved to Rhodesia where he worked as a news anchor, television presenter, and wrote several books. In 1981, he appeared in the horror movie Savage Harvest, filmed in Kenya, starring Michelle Phillips. In the 1980s, he worked mostly in American television, appearing in episodes of series like Remington Steele (starring Pierce Brosnan andJames Read, with James W. Jansen), T. J. Hooker (starring William Shatner and James Darren, with Robert O'Reilly), Dallas (starring Susan Howard, with Barry Jenner and Robert Pine), and Murder, She Wrote (directed by Vincent McEveety).
Partridge subsequently retired from acting and became an advertising agent, however, in the 2010s, he sporadically had acting roles again. He had a recurring voice role as Commander Brom Titus in Star Wars Rebels (2014-2018).