Maritime Union (French: Union des Maritimes) is a proposed political union of the three Maritime provinces of Canada – New Brunswick, Nova Scotia, and Prince Edward Island – to form a single new province.
The idea has been proposed at various times throughout Canadian history, most recently in November 2012 by Stephen Greene, John D. Wallace and Mike Duffy, three Conservative Senators from the region. As of 2024, a union of the three Maritime provinces would have a population of approximately 2.1 million, becoming the fifth largest by population, out of eight remaining Canadian provinces.