| Patrick O' Sullivan | |
| Order1: | Advocate-General of Madras Presidency |
| Term Start1: | 1877 |
| Term End1: | 1882 |
| Predecessor1: | Sir H. S. Cunningham |
| Successor1: | Hale Horatio Shephard |
| Birth Date: | 20 January 1835 |
| Profession: | Advocate-General |
Patrick O' Sullivan (20 January 1835 – 25 February 1887) was a British lawyer of Irish origin who served as the Advocate-General of the Madras Presidency and ex-officio member of the Madras Legislative Council from 1877 to 1882.
He studied law at Gray's Inn and was called to the bar in 1864.[1]
He married Sidney Jane Moore in India. They had only one son, Arthur, a British Army officer who played a leading role in the 1914 Christmas truce.[2]