Otto IV of Lower Bavaria

Otto IV (1307–1334) was a Wittelsbach Duke of Lower Bavaria, son of Duke Stephen I. From his father's death in 1310 he ruled jointly with his brother Henry XIV and cousin Henry XV. The co-regents warred among themselves in 1322, and in 1331 Lower Bavaria was partitioned, Otto taking Burghausen and Traunstein.

Estranged from his brother, he named his cousin Emperor Louis IV his contracted heir. He married Richardis of Jülich and died in Munich on 14 December 1334.