He has been on British television in Crossroads playing Max Samson, Chalk and Secret Army. He also appeared in the 1985 motion picture Santa Claus: The Movie, in which he can be seen seated next to the chairman in the court room at the trial of the character BZ. In 1986 he played "Hanks" who leads the ill-fated salvage team that picks up Ellen Ripley in Aliens. In 2006, he guest-starred on the Doctor Who audio drama The Reaping, while in 2007 he starred in an episode of Lewis. Milligan appeared in an episode of Midsomer Murders, entitled "Country Matters".