John Alderton is an English actor. He is best known for his roles in Upstairs, Downstairs, Thomas & Sarah, Wodehouse Playhouse, Little Miss, Please Sir!, No, Honestly and Fireman Sam. Alderton has often starred alongside his wife, Pauline Collins.

Please Sir! is a British television sitcom created by John Esmonde and Bob Larbey and featuring actors John Alderton, Deryck Guyler, Penny Spencer, Joan Sanderson, Noel Howlett, Erik Chitty and Richard Davies. Produced by London Weekend Television for ITV, the series ran for 55 episodes between 1968 and 1972.