The Battle of Abensberg took place on 20 April 1809 between a Franco-German force under the command of Emperor Napoleon I of France and a reinforced Austrian corps led by Feldmarschall-Leutnant Archduke Louis of Austria. As the day wore on, Feldmarschall-Leutnant Johann von Hiller arrived with reinforcements to take command of the three corps that formed the Austrian left wing. The action ended in a complete Franco-German victory. The battlefield was southeast of Abensberg and included clashes at Offenstetten, Biburg-Siegenburg, Rohr in Niederbayern, and Rottenburg an der Laaber. On the same day, the French garrison of Regensburg capitulated.

Abensberg is a town in the Lower Bavarian district of Kelheim, in Bavaria, Germany, lying around 30 km (19 mi) southwest of Regensburg, 40 km (25 mi) east of Ingolstadt, 50 km (31 mi) northwest of Landshut and 100 km (62 mi) north of Munich. It is situated on the river Abens, a tributary of the Danube.