Theodoric III (born between 649 and 656—died 690/691) was a Merovingian ruler who succeeded his brother Chlotar III as king of Neustria and Burgundy in 673, at the instigation of Ebroin, the Neustrian mayor of the palace. He was soon deposed by another brother, Childeric II, was restored in 675, then was momentarily deposed again in favour of a certain Clovis (allegedly Chlotar III’s son), but recovered his throne in 676 and finally (679) also became king of Austrasia. A puppet pure and simple, he then had to watch his subjects fight one another until the final victory of Pippin II and the Austrasians at the Battle of Tertry in 687.