Steve Nallon (born 8 November 1960) is a British actor, writer and impressionist, best known for impersonating Margaret Thatcher on television throughout her time as Prime Minister of the UK (1979–1990).

Nallon began his career as a stand-up performer on the northern club circuit, before joining the team of the British satirical puppet show Spitting Image in 1984. He has performed in a number of other roles as an actor and voice artist in theatre, film, television and radio.