| Honorific-Prefix: | The Right Honourable |
| The Earl of Inchiquin | |
| Honorific-Suffix: | KB PC(I) |
| Spouse: | Lady Anne Hamilton |
| Father: | William O'Brien, 3rd Earl of Inchiquin |
| Mother: | Mary O'Brien |
| Birth Place: | Ireland |
| Death Place: | Ireland |
| Occupation: | Politician |
| Website: | | module = } |