Saint-Hyacinthe—Bagot (formerly known as Saint-Hyacinthe and St. Hyacinthe—Bagot) is a federal electoral district that has been represented in the House of Commons of Canada since 1935.

In the 2015 election, the winner received the lowest vote percentage of any winning candidate in the country.

The district includes the Regional County Municipalities of Acton and Les Maskoutains.

It includes the communities of Saint-Hyacinthe, Acton Vale, Saint-Pie, Sainte-Madeleine, and Saint-Dominique.

After the resignation of Yvan Loubier on 21 February 2007, a by-election occurred on 17 September 2007.