รางวัลออสการ์ สาขาบทภาพยนตร์ดัดแปลงยอดเยี่ยม
บทภาพยนตร์ที่ได้รับรางวัลและได้รับการเสนอชื่อเข้าชิง > 1940s

| ปี | ภาพยนตร์ | นักเขียนบท | ดัดแปลงจาก |
| --- | --- | --- | --- |
1940 (13th): 
| 1940 (13th) | The Philadelphia Story | Donald Ogden Stewart | The play The Philadelphia Story by Philip Barry |
| 1940 (13th) | The Grapes of Wrath | Nunnally Johnson | The novel The Grapes of Wrath by John Steinbeck |
| 1940 (13th) | Kitty Foyle: The Natural History of a Woman | Dalton Trumbo | The novel Kitty Foyle by Christopher Morley |
| 1940 (13th) | The Long Voyage Home | Dudley Nichols | The short play The Moon of the Caribees, by Eugene O'Neill The short play In the Zone by Eugene O'Neill The short play Bound East for Cardiff by Eugene O'Neill The short play The Long Voyage Home by Eugene O'Neill |
| 1940 (13th) | Rebecca | Robert E. Sherwood Joan Harrison | The novel Rebecca by Daphne du Maurier |
1941 (14th): 
| 1941 (14th) | Here Comes Mr. Jordan | Sidney Buchman Seton I. Miller | The play Heaven Can Wait by Harry Segall |
| 1941 (14th) | Hold Back the Dawn | Charles Brackett Billy Wilder | The story "Memo to a Movie Producer" by Ketti Frings |
| 1941 (14th) | How Green Was My Valley | Philip Dunne | The novel How Green Was My Valley by Richard Llewellyn |
| 1941 (14th) | The Little Foxes | Lillian Hellman | The play The Little Foxes by Lillian Hellman |
| 1941 (14th) | The Maltese Falcon | John Huston | The novel The Maltese Falcon by Dashiell Hammett|- |
1942 (15th): 
| 1942 (15th) | Mrs. Miniver | George Froeschel James Hilton Claudine West Arthur Wimperis | The character Mrs. Miniver, from the newspaper columns by Jan Struther |
| 1942 (15th) | 49th Parallel | Rodney Ackland Emeric Pressburger | A story by Emeric Pressburger |
| 1942 (15th) | The Pride of the Yankees | Herman J. Mankiewicz Jo Swerling | A story by Paul Gallico |
| 1942 (15th) | Random Harvest | George Froeschel Claudine West Arthur Wimperis | The novel Random Harvest by James Hilton |
| 1942 (15th) | The Talk of the Town | Sidney Buchman Irwin Shaw | A story by Sidney Harmon |
1943 (16th): 
| 1943 (16th) | Casablanca | Philip G. Epstein Julius J. Epstein Howard Koch | The play Everybody Comes to Rick's by Murray Burnett and Joan Alison |
| 1943 (16th) | Holy Matrimony | Nunnally Johnson | The novel Buried Alive by Arnold Bennett |
| 1943 (16th) | The More the Merrier | Richard Flournoy Lewis R. Foster Frank Ross Robert Russell | A story by Frank Ross and Robert Russell |
| 1943 (16th) | The Song of Bernadette | George Seaton | The novel The Song of Bernadette by Franz Werfel |
| 1943 (16th) | Watch on the Rhine | Dashiell Hammett | The play Watch on the Rhine by Lillian Hellman |
1944 (17th): 
| 1944 (17th) | Going My Way | Frank Butler Frank Cavett | A story by Leo McCarey |
| 1944 (17th) | Double Indemnity | Billy Wilder Raymond Chandler | The novel Double Indemnity in Three of a Kind by James M. Cain |
| 1944 (17th) | Gaslight | John Van Druten Walter Reisch John L. Balderston | The play Angel Street by Patrick Hamilton |
| 1944 (17th) | Laura | Jay Dratler Samuel Hoffenstein Betty Reinhardt | The novel Laura by Vera Caspary |
| 1944 (17th) | Meet Me in St. Louis | Irving Brecher Fred F. Finklehoffe | The novel Meet Me in St. Louis by Sally Benson |
1945 (18th): 
| 1945 (18th) | The Lost Weekend | Charles Brackett Billy Wilder | The novel The Lost Weekend by Charles R. Jackson |
| 1945 (18th) | Mildred Pierce | Ranald MacDougall | The novel Mildred Pierce by James M. Cain |
| 1945 (18th) | Pride of the Marines | Albert Maltz | The book Al Schmid, Marine by Roger Butterfield |
| 1945 (18th) | Story of G.I. Joe | Leopold Atlas Guy Endore Philip Stevenson | The book Brave Men by Ernie Pyle The book Here Is Your War by Ernie Pyle |
| 1945 (18th) | A Tree Grows in Brooklyn | Frank Davis Tess Slesinger (posthumous nomination) | The novel A Tree Grows in Brooklyn by Betty Smith |
1946 (19th): 
| 1946 (19th) | The Best Years of Our Lives | Robert Sherwood | The novel Glory for Me by MacKinlay Kantor |
| 1946 (19th) | Anna and the King of Siam | Sally Benson Talbot Jennings | The novel Anna and the King of Siam by Margaret Landon |
| 1946 (19th) | Brief Encounter | Anthony Havelock-Allan David Lean Ronald Neame | The play Still Life by Noël Coward |
| 1946 (19th) | The Killers | Anthony Veiller | The short story "The Killers" by Ernest Hemingway |
| 1946 (19th) | Rome, Open City | Sergio Amidei Federico Fellini | A story by Sergio Amidei and Alberto Consiglio |
1947 (20th): 
| 1947 (20th) | Miracle on 34th Street | George Seaton | A story by Valentine Davies |
| 1947 (20th) | Boomerang | Sally Benson Talbot Jennings | The Reader's Digest article by Anthony Abbot |
| 1947 (20th) | Crossfire | John Paxton | The novel The Brick Foxhole by Richard Brooks |
| 1947 (20th) | Gentleman's Agreement | Moss Hart | The novel Gentleman's Agreement by Laura Z. Hobson |
| 1947 (20th) | Great Expectations | David Lean Ronald Neame Anthony Havelock-Allan | The novel Great Expectations by Charles Dickens |
1948 (21st): 
| 1948 (21st) | The Treasure of the Sierra Madre | John Huston | The novel The Treasure of the Sierra Madre by B. Traven |
| 1948 (21st) | A Foreign Affair | Charles Brackett Billy Wilder Richard L. Breen | A story by David Shaw |
| 1948 (21st) | Johnny Belinda | Irma von Cube Allen Vincent | The play Johnny Belinda by Elmer Blaney Harris |
| 1948 (21st) | The Search | Richard Schweizer David Wechsler | – (original) |
| 1948 (21st) | The Snake Pit | Frank Partos Millen Brand | The novel The Snake Pit by Mary Jane Ward |
1949 (22nd): 
| 1949 (22nd) | A Letter to Three Wives | Joseph L. Mankiewicz | The novel Letter to Five Wives by John Klempner |
| 1949 (22nd) | All the King's Men | Robert Rossen | The novel All the King's Men by Robert Penn Warren |
| 1949 (22nd) | The Bicycle Thief | Cesare Zavattini | The novel Bicycle Thief by Luigi Bartolini |
| 1949 (22nd) | Champion | Carl Foreman | The short story "Champion" by Ring Lardner |
| 1949 (22nd) | The Fallen Idol | Graham Greene | The short story "The Basement Room" by Graham Greene |