As an actor, Welland appeared as PC David Graham in the BBC Television series Z-Cars from 1962 to 1978. He was a sympathetic schoolteacher in a BAFTA-winning performance in the film Kes (1969), and a detective in the Richard Burton film Villain (1971). He appeared as a villain in one 1975 episode of The Sweeney, and was in the series' first cinema spin-off Sweeney! (1977) as Frank Chadwick, a newspaper Editor. His other film appearances include Dennis Potter's Blue Remembered Hills (1979) as the character Willie, and Dancin' thru the Dark (1990). He was also in the television series Cowboys (1980), a comedy about a dodgy builder, with Roy Kinnear.