It began as a camp for the First Nations in the region. The town was founded in 1776, when Loyalists immigrated from nearby Vermont. They called it The Outlet, referring to the flow of water emptying into the Magog River from the lake. The city was named after Lake Memphremagog, on which the city is situated.
It was formally named Magog in 1855.
In 2002 the City of Magog was merged with the Township of Magog and the Village of Omerville as part of the municipal reorganization in Quebec
