This article is about the river in New Brunswick. For more information about the communities which comprise the Miramichi region, see the separate article on the Miramichi River valley.

The Miramichi River is a Canadian river located in the east-central part of New Brunswick. The river drains into Miramichi Bay in the Gulf of St. Lawrence. The name may have been derived from the Montagnais words "Maissimeu Assi" (meaning Mi'kmaq Land), and it is today the namesake of the Miramichi Herald at the Canadian Heraldic Authority.