| Olivier J. Leblanc | |
| Constituency Mp: | Kent |
| Parliament: | Canadian |
| Predecessor: | George Valentine McInerney |
| Successor: | Ferdinand-Joseph Robidoux |
| Term Start: | 1900 |
| Term End: | 1911 |
| Office2: | Member of the Legislative Council of New Brunswick |
| Term Start2: | 1891 |
| Term End2: | 1892 |
| Office3: | Member of the Legislative Assembly of New Brunswick for Kent County |
| Predecessor3: | Urbain Johnson |
| Successor3: | Auguste Théophile Léger |
| Term Start3: | 1882 |
| Term End3: | 1891 |
| Birth Date: | 27 November 1830 |
| Birth Place: | Memramcook, New Brunswick |
| Party: | Liberal |
Olivier J. LeBlanc (November 27, 1830 - December 14, 1919) was a Canadian politician of Acadian descent.
Born in Memramcook, New Brunswick, the son of Joseph LeBlanc and Victorie B. Girouard, LeBlanc was educated at Common Schools. A farmer, he was elected to the Legislative Assembly of New Brunswick in 1882. His election in 1882 was protested but he was reelected in a by-election held later that year. Leblanc subsequently was a Minister without portfolio in the Executive Council from 1889 to 1891. He ran unsuccessfully for a federal seat in 1891 and was then named to the Legislative Council of New Brunswick.
LeBlanc was first elected to the House of Commons of Canada for the riding of Kent in the general elections of 1900. A Liberal, he was re-elected in 1904 and 1908.