Professor Popper's Problem is a 1975 British children's science fiction comedy film directed by Gerry O'Hara, starring Charlie Drake in the titular role. Featuring a number of child actors, Todd Carty, Milo O'Shea, and Sydney Bromley also appear. The serial picture was produced for the Children's Film Foundation (CFF) by Roy Simpson of , presenting a screenplay by Leo Maguire and soundtrack by Kenneth V. Jones. The story concerns an eccentric science teacher named Professor P. Popper, miniaturised with a group of pupils after accidentally consuming shrinking pills. A student apart from the group volunteers her help, as, separately, does a colleague of Popper's. As they search for an antidote, Popper and his entourage must see off multiple dangers, including criminals determined to steal hi