The Ox-Bow Incident is a 1943 American Western film directed by William A. Wellman, starring Henry Fonda, Dana Andrews and Mary Beth Hughes, with Anthony Quinn, William Eythe, Harry Morgan and Jane Darwell. Two cowboys arrive in a Western town, when news arrives that a local rancher has been murdered and his cattle stolen. The townspeople, joined by the two cowboys and cowboys from other ranches, form a posse to catch the perpetrators. They find three men in possession of the cattle, and are determined to see justice done on the spot.

The film premiered in May 1943 to positive reviews from critics. It is one of a select group of films to secure just one Oscar nomination, albeit in the Best Picture category. As of 2024, it is the last film to be nominated solely in that category. The Ox-Bow Incident and The Outlaw (also produced in 1943) are the earliest films in the AllMovie list of psychological Westerns.

In 1998, 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". The film was adapted from the 1940 novel of the same name, written by Nevadan Walter Van Tilburg Clark.