Lewis appeared in several films, again mostly in minor roles. Notable film appearances included Terry Gilliam's 1985 film Brazil, where he played one of the Black Maria guards, and playing Hal in Robin Hood: Prince of Thieves.

He appeared in two other prominent historical comedy series - as Blag in the Channel 4 sitcom Chelmsford 123 (1988) set during the Roman occupation of Britain in AD 123, and as assorted medieval peasants, (including Piers and Mr Applebottom) in The Black Adder (1983), set in 1485. His longest recurring role was as dim barman Elmo Putney in the comedy series Brush Strokes (1991), and he had minor parts in two Ronnie Barker sitcoms - The Magnificent Evans (1984) and Open All Hours (1985) - and the ITV comedy-drama Minder (1984).

As an actor, Lewis was probably most associated in the British public consciousness with his role as Rabies, one of the Merry Men in the award-winning 1989 BBC children's television comedy series Maid Marian and Her Merry Men.

Lewis featured as one of Robin Hood's followers in the 1991 film Robin Hood: Prince of Thieves, playing a character named Hal.

He also appeared in the 1992 Oscar-nominated semi-biographical film Chaplin, and was the English language voice of Obelix in the 1994 film of Asterix in America to Craig Charles' Asterix. In 2005, he played the part of Lillas Pastia, the innkeeper, in Bizet's Carmen at the Royal Albert Hall, London, and in 2007, played alongside Warwick Davis in the film Small Town Folk.

On 28 January 2018, it was reported that police in Edinburgh were investigating the circumstances surrounding the actor's death after his daughter Debora Milazzo claimed he had been placed on a regime of high-dose sedatives and maximum-strength opiate painkillers, and had been needlessly placed on the kind of treatment plan that would be prescribed for the terminal phase of a malignant disease, explaining that her father had not received a terminal diagnosis. Police Scotland confirmed it was investigating the complaint.