Hejsager is an urban Settlement in Haderslev Municipality, in the region of Southern Denmark, Denmark. Hejsager lies at 17 m above sea level. It has 274 inhabitants (2026). The nearest city is Haderslev, 8.9 km to the west. Beaches nearby: Hejsager (2.5 km), Kelstrup (3.4 km), Flovt (5.7 km). Among the landmarks around are Haderslev Cathedral (8.9 km), Immervad Bridge (18.0 km) and Skamlingsbanken (23 km). Among the natural features are Knivsbjerg (14.1 km).