The area that is now New Brunswick has been continuously inhabited since 5000 B.C., when nomadic Indians occupied the region. The two major tribes in the area when European explorers arrived in the 16th century were the Micmac in the northeast and the Malecite west of the St. John River. The Micmac were primarily hunters and fishers, while the Malecite grew corn.

In 1534 Jacques Cartier, a French explorer, sailed into what is now the Bay of Chaleur and claimed the entire coastal area for France. The area that is now New Brunswick and Nova Scotia came to be called Acadia. There was no attempt to colonize Acadia until 1604, when a group of settlers brought by the Sieur de Monts and Samuel de Champlain spent the winter at the mouth of the St. Croix River (the southwestern border of present-day New Brunswick). The settlement was then moved to the south shore of the Bay of Fundy (in what is now Nova Scotia), and Port Royal, the community founded there, became the nucleus of the Acadian colony.

Jean de Biencourt de Poutrincourt, a member of the colonizing group, and his son Charles de Biencourt tried to develop the north-shore area. De Biencourt and Charles de la Tour formed a fur-trading company, and around 1632 La Tour built a fort on the site of present Saint John.

Important dates in New Brunswick
1534 The French explorer Jacques Cartier arrived in Chaleur Bay.
1604 Samuel de Champlain and Sieur de Monts of France spent the winter on St. Croix Island.
1762 Traders from New England arrived in Saint John.
1763 France, in the Treaty of Paris, confirmed British ownership of the New Brunswick region.
1770's-1780's Thousands of Loyalists came from the United States to settle in New Brunswick.
1784 New Brunswick became a separate province.
1825 A great fire swept the Miramichi River region.
1842 The New Brunswick-Maine boundary dispute was settled.
1848 New Brunswick was granted self-government.
1867 New Brunswick became one of the original four provinces of the Dominion of Canada.
1890 Two national railway systems linked New Brunswick cities with Montreal.
1952-1953 Vast deposits of copper, lead, silver, and zinc were mapped in the Bathurst-Newcastle region.
1968 An industrial development program was completed in the Bathurst-Newcastle region, and a hydroelectric plant opened at Mactaquac Dam on the St. John River near Fredericton.
1997 Confederation Bridge, which connects Prince Edward Island and New Brunswick, opened.