His first stage appearance in 1944 was at the Open Air Theatre, Regent's Park in The Winter's Tale.

[6] Morris featured in over fifty films; a notable early role was as Thorburn, the oddball pornographer running a Soho bookshop in John Gilling's science fiction thriller The Night Caller (1965).

[7] His better known films include Stanley Kubrick's A Clockwork Orange (1971), Woody Allen's Love and Death (1975),[2] Ken Russell's Lisztomania (1975),[2] and Gene Wilder's The Adventure of Sherlock Holmes' Smarter Brother (1977).

[2] He also appeared in many television programmes, his debut being in a BBC production of the comedy Fly Away Peter (1948).

[1] Television appearances include The Champions (1968), as Van Velden in episode 2, "The Invisible Man".