He is best remembered for playing Amos Brearly in the British soap opera Emmerdale from the first episode in 1972 to 1991, and appeared again in this role in 1994 and 1995.
[2] During the Second World War, Magill served in the Royal Corps of Signals and was a member of "Stars in Battledress".
[1] He starred in the West End production of The Ruling Class and appeared at the Bristol Old Vic in Death of a Salesman and The Browning Version.
He played Amos Brearly, a character who co-ran The Woolpack pub with Henry Wilks, and they became a double act for the next nineteen years.
He reappeared as Amos for short-lived appearances in 1992, 1993, 1994 and 1995, the latter when the character accompanied Annie Sugden to her son Joe's funeral.