Glenister made his first television appearance in the sitcom Sink or Swim in 1980. He has also appeared in shows such as Soldier Soldier, Doctor Who (in the serial The Caves of Androzani, opposite his Sink or Swim co-star Peter Davison), Only Fools and Horses (as Myles the millionaire garden centre owner and chairman of the SWANS committee), A Touch of Frost and Hustle as Ash Morgan, as well as several films.