River Fynn

Fynn
Location of the river mouth within Suffolk
Location
CountryEngland
RegionSuffolk
Physical characteristics
Source 
  locationWitnesham
  coordinates52°16′48″N 1°18′17″E / 52.2799°N 1.3048°E / 52.2799; 1.3048
  elevation60 m (200 ft)
Mouth 
  location
Martlesham
  coordinates
52°04′36″N 1°17′43″E / 52.07667°N 1.295313°E / 52.07667; 1.295313
  elevation
0 m (0 ft)
Length13.622 km (8.464 mi)
Basin features
River systemRiver Deben
Water Body IDGB105035040330

The River Fynn is a waterway in Suffolk which joins the River Deben. Its source is to the north-west of the village of Witnesham and it joins the Deben south of Woodbridge, via Martlesham Creek.

Among its tributaries are the River Lark, whose sources are to the north of Grundisburgh, and an unnamed stream which flows east from a point north of the village of Kesgrave, through the grounds of Kesgrave Hall. Both join the Fynn to the west of Martlesham.