Bad Bevensen (West Low German: Bemsen) is a town in the north of the district Uelzen in Lower Saxony, Germany.

The Ilmenau river, a tributary of the Elbe, flows through Bad Bevensen.

Bad Bevensen is the seat of the Samtgemeinde ("collective municipality") Bevensen-Ebstorf.

Jastorf is situated some 3 kilometres (2 miles) south of the town center.

In the run-up to the G20 summit in 2017, left-wing extremists set a fire in the town.