Sherlock Jr. is a 1924 American silent comedy film starring and directed by Buster Keaton and written by Clyde Bruckman, Jean Havez, and Joseph A. Mitchell. It features Kathryn McGuire, Joe Keaton, and Ward Crane.

In 1991, Sherlock Jr. was selected for preservation in the United States National Film Registry by the Library of Congress as being "culturally, historically, or aesthetically significant". In 2000, the American Film Institute, as part of its AFI 100 Years... series, ranked the film #62 in its AFI's 100 Years... 100 Laughs. David Thomson calls it "a breakthrough. It is as if a filmmaker had at least learned the point of the whole thing."