Michael O'Sullivan (politician)

Michael O'Sullivan (May 4, 1784 – March 7, 1839) was a lawyer, militia officer, politician and judge in Lower Canada. Born in Clonmel, Ireland, he emigrated to Lower Canada as a child and was educated at the Collège Saint-Raphaël, where he began a life-long association with the Roman Catholic Sulpician order. He became a prominent member of the bar of Lower Canada, as well as a member of the Legislative Assembly of Lower Canada and Solicitor-general for Lower Canada.

O'Sullivan was an officer in the Lower Canada militia during the War of 1812. He participated in the Battle of the Châteauguay as aide-de-camp to Lieutenant-Colonel Charles de Salaberry, the commander of the Canadian and Mohawk forces who were defending Lower Canada from an invading American force. O'Sullivan was mentioned in dispatches for bravery after the battle, and subsequently wrote a contemporary account of the battle which has become the basis for understanding the battle.

O’Sullivan was elected to the Legislative Assembly of Lower Canada in 1814 and remained in office until 1824. He generally supported the Parti canadien, but gradually moved away from it as it became more nationalist. During his time as a member of the Legislative Assembly, O'Sullivan was vocal in his opposition to building a new, non-denominational, hospital in Montreal; his outspokenness on the matter culminated in his fighting a duel with a Montreal doctor, William Caldwell, who supported the proposal. The hospital was ultimately built.

In November 1838, O'Sullivan was appointed the Chief Justice of the Court of Queen's Bench in Montreal, but died in March 1839 at the age of 54.