National Lampoon's Animal House is a 1978 American comedy film directed by John Landis and written by Harold Ramis, Douglas Kenney and Chris Miller. It stars John Belushi, Tim Matheson, John Vernon, Verna Bloom, Thomas Hulce, and Donald Sutherland. The film is about a trouble-making fraternity whose members challenge the authority of the dean of the fictional Faber College.

Produced by Matty Simmons of National Lampoon and Ivan Reitman for Universal Pictures, it was inspired by stories written by Miller and published in National Lampoon, which were based on Ramis' experience in the Zeta Beta Tau fraternity at Washington University in St. Louis, Miller's Alpha Delta Phi experiences at Dartmouth College in New Hampshire, and producer Reitman's at McMaster University in Hamilton, Ontario.

Of the younger lead actors, only the 28-year-old Belushi was an established star, but even he had not yet appeared in a film, having gained fame as an original cast member of Saturday Night Live, which was in its third season in the autumn of 1977. Several of the actors who were cast as college students, including Thomas Hulce, Karen Allen, and Kevin Bacon, were just beginning their film careers. Matheson, also cast as a student, was already a seasoned actor, having appeared in movies and television since the age of 13.

Filming took place at the University of Oregon from October to December 1977. Following its initial release on July 28, 1978, Animal House received generally mixed reviews from critics, but Time and Roger Ebert proclaimed it one of the year's best. Filmed for only $3 million (equivalent to $14,014,286 in today's money) it garnered an estimated gross of more than $141 million ($658,671,429 in today's money) in the form of theatrical rentals and home video, not including merchandising, making it the highest grossing comedy film of its time.

The film, along with 1977's The Kentucky Fried Movie, also directed by Landis, was largely responsible for defining and launching the gross-out film genre, which became one of Hollywood's staples. Animal House is now regarded as one of the best comedy films of all time.

In 2001, the United States Library of Congress deemed National Lampoon's Animal House "culturally, historically, or aesthetically significant" and selected it for preservation in the National Film Registry. It was No. 1 on Bravo's "100 Funniest Movies". It was No. 36 on AFI's "100 Years... 100 Laughs" list of the 100 best American comedies. In 2008, Empire magazine selected it as No. 279 of "The 500 Greatest Movies of All Time".