| Successfully sued tabloid magazine Confidential over a story that claimed she was spotted necking in the back of a theater. O'Hara was out of the country at the time the incident supposedly took place |
| John Ford directed her in five movies: How Green Was My Valley (1941), Rio Grande (1950), The Quiet Man (1952), The Long Gray Line (1955) and The Wings of Eagles (19 |
| Acted alongside John Wayne in five movies: Rio Grande (1950), The Quiet Man (1952), The Wings of Eagles (1957), McLintock! (1963) and Big Jake (1971). |
| At 14, she joined Ireland's National Theatre, Abbey Theatre. |
| Discovered by actor Charles Laughton. |