The Sex Life of the Polyp (1928) is a short film written and performed by Robert Benchley, based on a routine he first did in 1922. The short, which was adapted from an essay by Benchley, documents a dim-witted doctor attempting to discuss the sex life of a polyp to a women's club. This was the second of Benchley's 46 comedy short films, with six made for Fox, one each for Universal Pictures and RKO Radio Pictures, 29 for Metro-Goldwyn-Mayer, and nine for Paramount Pictures.
The film, made in the then-new Fox Movietone sound-on-film process, was a success and was later included in the compilation Robert Benchley and the Knights of the Algonquin.
In 2007, the film was selected for preservation in the United States National Film Registry by the Library of Congress as being "culturally, historically, or aesthetically significant".