The Nashwaak River, located in west-central New Brunswick, Canada, is a tributary of the Saint John River. It is 113 kilometres long. The river rises from (southeast of the village of Juniper) and flows south and east through uninhabited land and rapids to the village of Stanley. From Stanley, the Nashwaak flows southeast to and Taymouth, then south the through several rural communities such as Durham Bridge, the historic town of Nashwaak Village and Penniac before it reaches the town of Marysville. It flows into the Saint John River opposite downtown Fredericton.