Great Catherine is a 1968 British comedy film directed by Gordon Flemyng, based on a 1913 one act play by George Bernard Shaw, and starring Peter O'Toole, Zero Mostel, Jeanne Moreau and Jack Hawkins.^[1] Like the play, it is loosely based on the story of Sir Charles Hanbury Williams and his time spent as an envoy at the Russian court.

It was shot at Shepperton Studios near London with sets designed by the art directors John Bryan and William Hutchinson. The score was composed by Dimitri Tiomkin.

A British officer, Captain Charles Edstaston, is sent to the Russian court of Catherine the Great as an envoy, where he has to contend with the crafty machinations of her chief minister Potemkin.

• Peter O'Toole as Charles Edstaston
• Jeanne Moreau as Catherine the Great
• Zero Mostel as Potemkin
• Jack Hawkins as British Ambassador
• Akim Tamiroff as Sergeant
• Marie Lohr as Dowager Lady Gorse
• Kate O'Mara as Varinka
• Angela Scoular as Claire
• Oliver MacGreevy as General Pyskov
• James Mellor as Colonel Pugachov
• Lea Seidl as Grand Duchess
• Claire Gordon as Elizabeth Vokonska
• Declan Mulholland as Count Tokhtamysh
• Janet Kelly as Anna Schuvalova
• Henry Woolf as Egrebyomka

TV Guide wrote, "They waited 55 years to make it (Shaw's play) into a film and would have been well advised to wait another 55 years. What a mishmash!...Mostel, unless held in check, always overacts, and this is a prime example of a stage actor, accustomed to having to play "big" for the people in the last row, overdoing things for the close-up camera";^[2] whereas The New York Times wrote, "GREAT CATHERINE has a great clown named Zero Mostel...the glorious hamming of the portly American makes the picture...Surely Mr. Mostel's antics would have won the playwright's approval...The story, Braced immeasurably by the Shavian lines, as arranged by the scenarist, Hugh Leonard, and stylishly piloted by the director, Gordon Flemyng, the picture is also beautiful in its lavish décor, costumes and color photography."^[3]