Roy James "Philip" Locke (29 March 1928 – 19 April 2004) was an English actor who had roles in film and television.

[1] Locke trained at RADA, and from the late 1950s was part of the ensemble at the Royal Court Theatre, where John Osborne described him as "special and reliable".

[2][3] On television, Locke is remembered by fans of the science fiction series Doctor Who for his appearance in the 1982 serial Four to Doomsday as Bigon.

[4] Other TV credits include: The Baron, The Avengers episodes 'The Frighteners' (1961), 'Mandrake' (1964), and 'From Venus With Love' (1967), The Saint, The Champions, Department S, Z-Cars, Pennies from Heaven, The Omega Factor, Codename Icarus, The Box of Delights, Bergerac, Inspector Morse, Jeeves and Wooster, Minder, Antony and Cleopatra, She Fell Among Thieves (BBC), Oliver Twist, Ivanhoe and Jekyll & Hyde.

[5][6] A member of the Royal Shakespeare Company, Locke also played Professor Moriarty on Broadway in Sherlock Holmes in 1974–76 and appeared in Amadeus at the National Theatre.