| Étienne Mathieu | |
| Office: | Member of the Legislative Assembly of Quebec for L'Assomption |
| Successor: | Onuphe Peltier |
| Term Start: | 1867 |
| Term End: | 1871 |
| Birth Date: | 21 November 1804 |
| Birth Place: | Lachenaie, Lower Canada |
| Death Place: | Lachenaie, Quebec |
| Party: | Conservative |
Étienne Mathieu (November 21, 1804 - January 16, 1872) was a farmer, land owner and political figure in Quebec. He represented L'Assomption in the Legislative Assembly of Quebec from 1867 to 1871 as a Conservative.
He was born in Lachenaie, Lower Canada, the son of Jean-Marie Mathieu and Josephte Quenneville. Mathieu was educated at the Collège Masson à Terrebonne. In 1830, he married Josephte Duprat. He was a major in the militia, a justice of the peace and president of the agricultural society at Lachenaie. He was also a school commissioner and was mayor of Lachenaie from 1867 to 1869. Mathieu died in Lachenaie at the age of 67.