Fort Menagoueche, French colonial fort site in Saint John, Canada

Fort Menagoueche was a fortified warehouse at the mouth of the Saint John River, built in 1751 by Charles Deschamps de Boishébert and Ignace-Philippe Aubert de Gaspé. The site lies on the west bank opposite the Harbour Bridge toll booth, where a cairn and plaque stand about 400 metres south on Market Place. No fort structures remain; the location is marked by the commemorative cairn.

The site was first established in 1751 as a French defensive position during conflict in the region. French troops destroyed the fort in 1755 before British forces reconstructed it under a new name.

The site's name shifts with its rulers: French Fort Menagoueche, then British Fort Frederick after 1758. A cairn and commemorative plaque stand about 400 metres south on Market Place, not on the fort ground itself. The location later served industrial uses before the Harbour Bridge toll booth took its place in 1968.

The site lies opposite the Harbour Bridge toll booth on the west bank of the Saint John River. A cairn and commemorative plaque installed by the Historic Sites and Monuments Board of Canada stand about 400 metres south, on Market Place. The ground is uneven and exposed to weather.

The fort served as a strategic control point that changed hands several times, with each power leaving different defensive structures. These successive rebuilds left overlapping layers of fortifications that archaeologists continue to study.