Rex Motion Picture Company was an early film production company in the United States.

After Edwin S. Porter's short-lived Defender Film Company failed, The Rex Motion Picture Company was established by Edwin S. Porter, Joseph Engel, and William Swanson. Rex, based at 573–579 11th Avenue, New York City. produced dozens of films from 1910 into 1917. It adopted a crown emblem.^{[citation needed]}

Lois Weber established herself in the film industry at Rex.

Rex acquired Gem Motion Picture Company film properties and released them in 1912 under its own banner and later Universal's.^{[citation needed]} Rex was one of the studios that combined to form Universal Pictures under Carl Laemmle's leadership.^{[citation needed]}