Home movie footage is needed for a television documentary charting the history of the holiday camp, which is due to be made later this year.
The first Butlins opened in Skegness, Lincolnshire, on April 11, 1936. The resort is still open today, alongside those at Minehead, Somerset, and Bognor Regis, Sussex.
Butlins director Richard Bates said: “We’re convinced that hiding in people’s attics are some lost movie gems that could reveal many of the secrets of Butlins’ huge success over the past 75 years.
“Millions of hours of home movies have been shot at the resorts over the years and we are hoping to find as many of these priceless memories as possible.
“The British Film Institute and the National Film Archive have been wonderfully supportive in our search so far, but now we are turning to the general public for their help.”
Butlins, which has brought back its original 1936 Redcoat uniform to mark its anniversary, can be contacted on [email protected] or 020 7758 3900 by anyone who has cine-film or video footage.