He was educated at St Gregory the Great School, but left at 14 to train as a butcher at Toppings,[6] gaining a City and Guilds Diploma in the trade.

Finlay made his first stage appearances at the local Farnworth Little Theatre, in plays that included Peter Blackmore's Miranda in 1951.

[8] The critic John Simon wrote that the close-ups in the film allowed Finlay to give a more subtle and effective performance than he had done on stage.

At the Chichester Festival Theatre, Finlay played roles ranging from the First Gravedigger in Hamlet to Josef Frank in Weapons of Happiness.

He also appeared in The Party, Plunder, Saint Joan, Hobson's Choice, Amadeus (as Salieri),[9] Much Ado About Nothing (as Dogberry), The Dutch Courtesan, The Crucible, Mother Courage, and Juno and the Paycock.

[10] Between November 1988 and April 1989, Finlay toured Australia, performing in Jeffrey Archer's Beyond Reasonable Doubt at theatres in Sydney, Melbourne and Adelaide.

Finlay's first major television success was as Jean Valjean in the BBC's 1967 ten-part adaptation of Victor Hugo's Les Misérables.

Finlay appeared on American television in A Christmas Carol (1984) playing Marley's Ghost opposite George C. Scott's Ebenezer Scrooge.

He starred alongside Pete Postlethwaite and Geraldine James in the BBC drama series The Sins in 2000, playing the funeral director "Uncle" Irwin Green.