O-R
| Title | Director | Cast | Genre | Notes |
|---|---|---|---|---|
| Off the Record | James Flood | Pat O'Brien, Joan Blondell, Bobby Jordan | Drama | Warner Bros. |
| Of Mice and Men | Lewis Milestone | Burgess Meredith, Betty Field, Lon Chaney, Jr. | Drama | Hal Roach Studios |
| Oily to Bed, Oily to Rise | Jules White | The Three Stooges | Comedy Short | Columbia Pictures |
| The Oklahoma Kid | Lloyd Bacon | James Cagney, Humphrey Bogart, Rosemary Lane, Donald Crisp | Western | Warner Bros. |
| The Old Maid | Edmund Goulding | Bette Davis, Miriam Hopkins, George Brent | Drama | Warner Bros. |
| On Borrowed Time | Harold S. Bucquet | Lionel Barrymore, Cedric Hardwicke, Beulah Bondi, Una Merkel | Comedy | MGM |
| On Dress Parade | William Clemens | The Dead End Kids | Drama | Warner Bros. |
| Only Angels Have Wings | Howard Hawks | Cary Grant, Jean Arthur, Richard Barthelmess, Rita Hayworth | Drama | Columbia Pictures |
| On Trial | Terry O. Morse | John Litel, Margaret Lindsay | Drama | Warner Bros. |
| The Private Lives of Elizabeth and Essex | Michael Curtiz | Bette Davis, Errol Flynn, Olivia de Havilland, Donald Crisp | Romantic Drama | Warner Bros. |
| The Rains Came | Clarence Brown | Tyrone Power, Myrna Loy, George Brent, Brenda Joyce | Romantic Drama | 20th Century Fox |
| Range War | Lesley Selander | William Boyd | Western | Harry Sherman Productions |
| Remember? | Norman Z. McLeod | Robert Taylor, Greer Garson, Lew Ayres, Billie Burke | Romantic comedy | MGM |
| The Return of Doctor X | Vincent Sherman | Wayne Morris, Rosemary Lane, Humphrey Bogart | Science fiction | Warner Bros. |
| The Roaring Twenties | Raoul Walsh | James Cagney, Priscilla Lane, Humphrey Bogart | Crime thriller | Warner Bros. |
| Rulers of the Sea | Frank Lloyd | Douglas Fairbanks Jr., Margaret Lockwood, Will Fyffe | Historical drama | Paramount Pictures |
Read more about this topic: List Of American Films Of 1939