The Fiendish Plot of Dr. Fu Manchu is a 1980 comedy film. It was the final film featuring star Peter Sellers and David Tomlinson. Based on characters created by Sax Rohmer, the film stars Sellers in the dual role of Fu Manchu, a megalomaniacal Chinese evil genius, and English country gentleman detective Nayland Smith.

Pre-production began with Richard Quine as director. By the time production commenced, Piers Haggard had replaced him. Sellers handled the re-shoots himself. Released two weeks after Sellers' death, the film was a commercial and critical failure. It was also the final screen appearance for Tomlinson, who retired from acting shortly before its release.