Ian Kennedy Martin (born May 23 1936) is a British television scriptwriter. He is best known for his creation of the popular 1970s police drama series The Sweeney, produced by Euston Films for Thames Television, which ran on the ITV network from 1975 to 1978. It also spawned two feature film spin-offs.

He began his television career in the 1960s, first as a script editor on the military police drama series Redcap (1964) and then later as a writer on series such as The Troubleshooters (1965). In 1971 he worked on the famous BBC drama series The Onedin Line, which ran for nine years until 1980.

Since the end of The Sweeney in 1978, he has continued writing for various police / detective dramas. These have included the BBC's Juliet Bravo and The Chinese Detective during the 1980s and ITV's The Knock in the 1990s.

He is the brother of the scriptwriter Troy Kennedy Martin, with whom he worked on Redcap and The Sweeney.