Bad Bevensen (West Low German: Bemsen) is a town in the north of the district Uelzen in Lower Saxony, Germany. It is situated to the east of the Lüneburg Heath (Lüneburger Heide). The Ilmenau river, a tributary of the Elbe, flows through Bad Bevensen. Bad Bevensen is a well-known spa town.

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

Incorporated into the municipality are the villages of Gollern, Groß Hesebeck, Jastorf, Klein Bünstorf, Klein Hesebeck, Medingen, Röbbel, Sasendorf and Seedorf. Jastorf is situated some 3 kilometres (2 miles) south of the town center. It is the site of an Iron Age cemetery which gave the name of the Jastorf culture.

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

Bad Bevensen is twinned with:

• Chojnice Poland

• Ilse Falk (born 1943), politician and Member of Parliament (CDU)
• Ulrich Sinn (born 1945), Professor of Classical Archaeology
• Joachim Eigenherr (born 1947), athlete
• Volker Bescht (born 1951), Brigadier General of the Bundeswehr
• Heinrich Lange (born 1955), Vice Admiral of the German navy

• Gustav Stresemann Institute

• Bad Bevensen travel guide from Wikivoyage