Johnson was born 28 December 1916 in West Bromwich, England and attended Bromsgrove School,[1] where his fictional character Dick Barton was listed on the honours boards.

[1] He was the original voice of Dick Barton from 7 October 1946, performing over 300 episodes before quitting in 1949 to pursue a stage career.

[1] His assured upper class voice cadence made him ideal for certain characters[citation needed], notably in the BBC Radio 4 dramatic adaptation of A Dance to the Music of Time by Anthony Powell.

[6] His movie career included roles in Frenzy, The First Great Train Robbery, For Your Eyes Only and his last film Withnail & I in 1987, where he played a militaristic and drunken bar owner.

Johnson also appeared in numerous television dramas until the mid-1990s, including Dixon of Dock Green, Coronation Street, Out of the Unknown, Doomwatch, Death of an Expert Witness, Colditz, Rumpole of the Bailey, Doctor Who (in the serials The Underwater Menace and Invasion of the Dinosaurs), Inspector Morse and A Touch of Frost, amongst many others.