Bowthorpe Marsh is a 5.9-hectare (15-acre) Local Nature Reserve in Norwich, Norfolk, England. It is owned and managed by Norwich City Council.

This site adjacent to the River Yare has unimproved grassland, tall fen, a seasonal pond and drainage ditches, which have aquatic plants such as reed sweet-grass.

52°37′48″N 1°13′16″E / 52.630°N 1.221°E / 52.630; 1.221