Fort Nashwaak, French colonial fort in Fredericton, Canada.

Fort Nashwaak stood on the north bank of the Saint John River at the mouth of the Nashwaak River, in present-day Fredericton. Built in the winter of 1691–1692 for Governor Joseph Robineau de Villebon, it served as the capital of Acadia. No trace of its fortifications survives; the site was destroyed by erosion, and a cairn and plaque now stand about 700 metres north in Carleton Park.

Built in the winter of 1691–1692 on Governor Joseph Robineau de Villebon's orders, Fort Nashwaak replaced Fort Jemseg as Acadia's capital after Port Royal was lost, not regained. It served as the base for raids on New England, including the 1696 Siege of Pemaquid. France ordered the construction of Fort Saint-Jean in 1698 and Fort Naxoat was demolished; erosion later removed all traces.

The site was a gathering place where French soldiers and Abenaki warriors worked together to protect the region. This partnership reflects how European and Indigenous communities cooperated during the early colonial period.

The site today is marked only by a commemorative plaque in Carleton Park at the corner of Union Street and Gibson Street. Visitors will find a flat, park-like setting where informational signs explain the historical context and layout.

The fort successfully resisted a two-day English attack in 1696, proving its military strength and strategic value. This defensive victory made it a symbol of French presence in North America during that era.