The name Antigonish is of Mi'kmaq origin and is believed to refer to "The place where tree branches are torn off by bears gathering beech nuts".
The first European settlement took place in 1784 when Colonel Timothy Hierlihy received a large land grant surrounding Antigonish Harbour. Hierlihy and his party founded the Dorchester settlement, named for Sir Guy Carleton, who was Governor General of Canada and subsequently Lord Dorchester.
In 1796 a local settler, with the assistance of a First Nations guide, blazed a trail from Antigonish Harbour to Brown's Mountain, using the shortest route. This trail became a guide for travellers and eventually evolved into a winding Main Street.
By the late 1820s, Dorchester was commonly referred to as Antigonish.