Geoffrey M. McGivern is a British actor in film, television, radio and stage, as well as a comedian. He is best known for originating the role of Ford Prefect in The Hitchhiker's Guide to the Galaxy.

He played Ford Prefect in the radio series (1978–80) and subsequent LP releases of The Hitchhiker's Guide to the Galaxy by Douglas Adams whom he knew from Cambridge University, and reprised the role for the four new series broadcast on BBC Radio 4 between 2004 and 2018. A more recent radio broadcast was in The Ape That Got Lucky and he has appeared in TV shows such as Noel's House Party, Press Gang, Chef!, Big Train, Blackadder the Third ("Dish and Dishonesty") as Ivor Biggun, Chelmsford 123, Jonathan Creek, 15 Storeys High, Armstrong and Miller, Toast of London and series three of Peep Show.