The Battle of Winterthur was an important action between elements of the Army of the Danube and elements of the Habsburg army, commanded by Friedrich Freiherr von Hotze, during the War of the Second Coalition, part of the French Revolutionary Wars. The small town of Winterthur lies 18 kilometers (11 mi) northeast of Zürich, in Switzerland. Because of its position at the junction of seven roads, the army that held the town controlled access to most of Switzerland and points crossing the Rhine into southern Germany. Although the forces involved were small, the ability of the Austrians to sustain their 11-hour assault on the French line resulted in the consolidation of three Austrian forces on the plateau north of Zürich, leading to the French defeat a few days later.

The Army of the Danube was a field army of the French Directory in the 1799 southwestern campaign in the Upper Danube valley. It was formed on 2 March 1799 by the simple expedient of renaming the Army of Observation, which had been observing Austrian movements on the border between French First Republic and the Holy Roman Empire. It was commanded by General Jean-Baptiste Jourdan, 1st Comte Jourdan (1762–1833).