The Wizard of Oz is a 1939 American musical fantasy film produced by Metro-Goldwyn-Mayer. An adaptation of L. Frank Baum's 1900 children's fantasy novel The Wonderful Wizard of Oz, the film was primarily directed by Victor Fleming (who left the production to take over the troubled Gone with the Wind), and stars Judy Garland, Frank Morgan, Ray Bolger, Bert Lahr, Jack Haley, Billie Burke and Margaret Hamilton. Noel Langley, Florence Ryerson, and Edgar Allan Woolf received credit for the screenplay, but others made uncredited contributions. The songs were written by Edgar "Yip" Harburg and composed by Harold Arlen. The musical score and incidental music were composed by Herbert Stothart.

Characterized by its use of Technicolor, fantasy storytelling, musical score, and memorable characters, The Wizard of Oz was moderately successful upon its original release of August 25, 1939. The film was considered a critical success and was nominated for six Academy Awards, including Best Picture, winning in two categories: Best Original Song for "Over the Rainbow" and Best Original Score by Stothart. While the film was sufficiently popular at the box office, it failed to make a profit for MGM until the 1949 re-release, earning only $3,017,000 on a $2,777,000 budget, not including promotional costs, which made it MGM's most expensive production at that time.The 1956 television broadcast premiere of the film on the CBS network reintroduced the film to the public; according to the U.S. Library of Congress, it is the most seen film in movie history. In 1989, it was selected by the Library of Congress as one of the first 25 films for preservation in the National Film Registry for being "culturally, historically, or aesthetically significant". It is also one of the few films on UNESCO's Memory of the World Register. It was among the top ten in the 2005 BFI (British Film Institute) list of "50 films to be seen by the age of 14", and is on the BFI's updated list of "50 films to be seen by the age of 15" released in May 2020.The Wizard of Oz has become the source of many quotes referenced in contemporary popular culture. The film ranks often on critics' lists of greatest films of all time, and is the most commercially successful adaptation of L. Frank Baum's work.