Otto I (1117 – 11 July 1183), called the Redhead (German: der Rotkopf), was Duke of Bavaria from 1180 until his death. He was the first Bavarian ruler from the House of Wittelsbach, a dynasty which reigned until the abdication of King Ludwig III of Bavaria in the German Revolution of 1918.
A scion of the House of Wittelsbach, which had ruled as Counts of Scheyern in Upper Bavaria since the 11th century, Otto was a close ally of the Holy Roman Emperor Frederick Barbarossa from the Hohenstaufen dynasty. As Otto VI, he ruled as Count Palatine of Bavaria from 1156 to 1180. After the deposition of Frederick's rival Duke Henry the Lion from the Welf dynasty, Otto was granted the Duchy of Bavaria as a fief by the Emperor in 1180. Despite initial reluctance to his rule from the wary Bavarian nobility, Otto was able to secure the rule over Bavaria for his dynasty with the support of the emperor and his family.