One of the UK's most prolific television actors for 50 years, Peter Halliday was the son of an auctioneer and estate agent. He was schooled in Shropshire. Halliday failed his exam as apprentice auctioneer, worked briefly for Rolls-Royce, then served in the British Army during the Second World War, based in Iraq, Palestine and Egypt, until 1947. He graduated from the Royal Academy of Dramatic Art in 1949. He became a member of the Shakespeare Memorial Theatre, which later became the Royal Shakespeare Company. He achieved his greatest fame in the BBC's science-fiction television drama A for Andromeda (1961). He also gained further cult status for several appearances in Doctor Who (1963), which included providing monster voices for two serials and appearing under heavy makeup to play the alien Pletrac in Robert Holmes' witty parody of television and its viewers, Doctor Who: Carnival of Monsters: Episode One (1973).