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.

The theme tune "School's Out" was by Sam Fonteyn.

Exterior location scenes in the TV series were filmed at Stonebridge Primary School.

The title derives from the then-standard request phrase used in Britain when they wish to interrupt the teacher with a question.

Although the series is based around a class of 16-year-old pupils, most of the actors in these roles were in their twenties.

The programme was set in the fictional Fenn Street Secondary Modern School and starred John Alderton as Bernard Hedges, a young teacher fresh out of training college. The supporting cast included Deryck Guyler, Joan Sanderson and Richard Davies. Character actors and actresses formed the guest cast, including Mollie Sugden as a parent of one of the pupils, Barbara Mitchell as Frankie Abbott's mother, and Ann Lancaster as Mrs Pearce in a pair of 1968 episodes.

There were three basic locations for the scenarios: Hedges' classroom, the staffroom and the playground/outer area.

The class nickname for Hedges is "Privet" deriving from privet hedges.