He was born in Boston in 1762, the son of John Coffin, and came to the town of Quebec with his family in 1775.
In 1786, he married Marguerite, the daughter of Louis-Joseph Godefroy de Tonnancour, and settled at the seigneury of Pointe-du-Lac.
He was elected to the Legislative Assembly of Lower Canada for Saint-Maurice in 1792; he was reelected in 1796, 1800 and 1808.
In 1795, a large portion of his properties were sold to cover an unpaid debt.
Coffin also served as colonel for the local militia and commissioner of police for Trois-Rivières.