Derrick Sherwin
Derrick G. Sherwin (born 16 April 1936 in High Wycombe, England) was script editor of Doctor Who from The Web of Fear to The Mind Robber. He was then producer from The War Games to Spearhead from Space, overseeing the transition from Patrick Troughton's Second Doctor to Jon Pertwee's Third Doctor, the production's conversion from monochrome to colour, and the re-tooling of the series to a one of Earth-bound, present-day adventures. (DOC: The UNIT Family)
Sherwin is also an actor, with a several roles on television in the 1950s and 1960s. He made a cameo appearance in Spearhead from Space as a UNIT commissionaire.
His wife, Jane Sherwin, guest starred in his first story as producer, The War Games.
Since the deaths of Peter Bryant and Barry Letts, Sherwin is the earliest surviving producer of Doctor Who. Indeed, Philip Hinchcliffe and he are the only two producers of the "classic series" still living.