Coordinates: 52°14′26″N 0°11′11″E / 52.24051°N 0.18642°E / 52.24051; 0.18642
Horningsea is a small village north of Cambridge in Cambridgeshire in England. The parish covers an area of 6.63 km. It lies on the east bank of the River Cam, and on the road from Cambridge to Clayhithe. The nearest railway station is Waterbeach.
Listed as Horningesea in the Domesday Book, the village's name derives from either "Island (or dry ground in marsh) of a man called Horning" or "Island by the horn-shaped hill".
Horningsea's location on the River Cam is central to its development as a settlement, whose use for navigation dates back to at least Roman times. Around 4000 years ago, the parish consisted of a chalk promontory between marshland and the sea, and there is evidence of Iron Age habitation. Around 1000 years ago it had become a peninsula extending northwards into the undrained fens.
Between the 2nd and 4th centuries Horningsea was used for pottery by the Romans and was connected with Lincoln by Car Dyke, a Roman canal.