Henry I of Lower Bavaria, member of the Wittelsbach dynasty (19 November 1235 – 3 February 1290 in Burghausen) was Duke of Lower Bavaria. As Duke of Bavaria, he is also called Henry XIII.
He was the younger son of Otto II and the Countess of Palatinate Agnes of Brunswick.
His maternal grandparents were Henry V, Count Palatine of the Rhine and Agnes of Hohenstaufen. Agnes was a daughter of Conrad, Count Palatine of the Rhine.
In 1254, he succeeded his father together with his brother Louis II in Bavaria and the Palatinate. The brothers divided their land in 1255 against the law. Henry received Lower Bavaria and Louis Upper Bavaria and the Palatinate. It was the first of many divisions of the duchy. Henry resided in Landshut and, in 1255, the work for the main castle of Burghausen Castle was begun.
As the division of the duchy was against the law, it caused anger of the Bishops in Bavaria who allied with Ottokar II of Bohemia in 1257. In August 1257, Ottokar invaded Bavaria, but Henry and Louis managed to repulse the attack. It was one of the rare concerted and harmonious actions of both brothers who often argued. Henry was also later several times at war against the Archbishopric of Salzburg and the Bishop of Passau. During the conflict of King Rudolph I of Germany with Ottokar II, Duke Henry repeatedly changed allegiance.