Magog is a city in southeastern Quebec, Canada, about 120 kilometres (75 mi) east of Montreal at the confluence of Lake Memphremagog—after which the city was named—with the Rivière aux Cerises and the Magog River. It is a major centre and industrial city in the Regional County Municipality of Memphremagog. The city lies in the Eastern Townships tourist region.

Lake Memphremagog is a fresh water glacial lake located between Newport, Vermont, United States and Magog, Quebec, Canada. The lake spans both Quebec and Vermont, but is mostly in Quebec. Most of the watershed that feeds the lake is located in Vermont, and is a source for accumulated phosphorus, sediments, and other pollutants. Cleanup efforts since the late 1980s have improved the water quality. The lake furnishes potable water for 200,000 people.