Coaticook is a town on the Coaticook River, located in southeastern Quebec, Canada. It resides in the region of Estrie, which is often referred to colloqually as the Eastern Townships. It is the seat of the Coaticook Regional County Municipality, and its southern border is also the Canada–United States border.

Estrie is an administrative region of Quebec that comprises the Eastern Townships. Estrie, a French neologism, was coined as a derivative of est, "east". Originally settled by anglophones, today it is about 90 per cent francophone. Anglophones are concentrated in Lennoxville, home of the region's only English-speaking university, Bishop's University. The Eastern Townships School Board runs 20 elementary schools, three high schools, and a learning centre.