Ian Cassan Messiter (2 April 1920 – 22 November 1999) was a BBC Radio producer and the creator of a number of panel games, including Just a Minute, 'Dealing With Daniels' and Many a Slip.
Messiter also brought the successful Twenty Questions format to BBC Radio.
He was also the Programme Associate on Family Fortunes.
Messiter was born in Dudley, Worcestershire and educated at Winto House Sherborne School in Dorset.
He acted as whistle blower on both One Minute Please and Just a Minute.
He appeared in the first series of the BBC science-fiction quiz show The Adventure Game in 1980 as the Rangdo, the leader of the alien Argonds, and contributed some ideas for puzzles in the series.
He published his autobiography My Life and Other Games in 1990.
Nicholas Parsons stated that Just a Minute is "perhaps the most deceptively simple, enduring, popular and much-copied comedy game on radio or television anywhere" In each episode, Parsons thanks Messiter for inventing the charming game.