Otto III, Prince of Anhalt-Bernburg (died 27 February 1404) was a German prince of the House of Ascania and ruler of the principality of Anhalt-Bernburg.
He was the youngest son of Bernhard III, Prince of Anhalt-Bernburg, by his third wife Matilda, daughter of Magnus I, Duke of Brunswick-Göttingen.
Bypassed in his rights of inheritance during the life of his older half-brothers Bernhard IV and Henry IV, he only took possession of the principality of Anhalt-Bernburg when Henry died in 1374. Alongside his princely title, he also assumed the style "Lord of Bernburg".
On his death, Otto was succeeded by his nephew Bernhard V, son of the late Henry IV, and by his youngest son Otto IV, who ruled jointly with Bernhard.
By his unknown first wife, Otto had two sons:
Before 1391 Otto married for a second time to Lutrudis (d. aft. 2 July 1426), daughter of Gebhard IV, Count of Mansfeld-Querfurt. They had one daughter:
Anhalt-Bernburg was a principality of the Holy Roman Empire and a duchy of the German Confederation ruled by the House of Ascania with its residence at Bernburg in present-day Saxony-Anhalt. It emerged as a subdivision from the Principality of Anhalt from 1252 until 1468, when it fell to the Ascanian principality of Anhalt-Dessau. Recreated in 1603, Anhalt-Bernburg finally merged into the re-unified Duchy of Anhalt upon the extinction of the line in 1863.
Magnus I (1304–1369), called the Pious, was duke of Brunswick-Lüneburg.
Bernhard, a member of the House of Ascania, was Count of Anhalt and Ballenstedt, and Lord of Bernburg through his paternal inheritance. From 1180 he was also Duke of Saxony.
Henry I, a member of the House of Ascania, was Count of Anhalt from 1212 and the first ruling Anhalt prince from 1218 until his death.
Henry II, Prince of Anhalt-Aschersleben was a German prince of the House of Ascania and ruler of the principality of Anhalt-Aschersleben.
Otto I, Prince of Anhalt-Aschersleben was a German prince of the House of Ascania and ruler of the principality of Anhalt-Aschersleben.
Otto II, Prince of Anhalt-Aschersleben was a German prince of the House of Ascania and the last ruler of the principality of Anhalt-Aschersleben.
Bernhard I, Prince of Anhalt-Bernburg was a German prince of the House of Ascania and ruler of the principality of Anhalt-Bernburg.
Bernhard II, Prince of Anhalt-Bernburg, was a German prince of the House of Ascania and ruler of the principality of Anhalt-Bernburg.
Bernhard III, Prince of Anhalt-Bernburg was a German prince of the House of Ascania and ruler of the principality of Anhalt-Bernburg.
Bernhard IV, Prince of Anhalt-Bernburg was a German prince of the House of Ascania and ruler of the principality of Anhalt-Bernburg.
Henry IV, Prince of Anhalt-Bernburg was a German prince of the House of Ascania and ruler of the principality of Anhalt-Bernburg.
Otto IV, Prince of Anhalt-Bernburg was a German prince of the House of Ascania and ruler of the principality of Anhalt-Bernburg.
Bernhard V, Prince of Anhalt-Bernburg was a German prince of the House of Ascania and ruler of the principality of Anhalt-Bernburg.
Bernhard VI, Prince of Anhalt-Bernburg was a German prince of the House of Ascania and ruler of the Principality of Anhalt-Bernburg.
Albert I was a German prince of the House of Ascania and the second ruler of the Principality of Anhalt-Zerbst from 1298 until his death.
Sigismund II, Prince of Anhalt-Dessau was a German prince of the House of Ascania and ruler of the principality of Anhalt-Dessau.
George I, Prince of Anhalt-Dessau, was a German prince of the House of Ascania and ruler of the principality of Anhalt-Dessau. He was the second son of Sigismund I, Prince of Anhalt-Dessau, by his wife Judith, daughter of Gebhard XI, Count of Querfurt.
William II, Duke of Brunswick-Lüneburg was the Prince of Lüneburg from 1330 to 1369.
Sophia of Brandenburg (1300–1356) was a daughter of Margrave Henry I (1256–1318) and his wife Agnes of Bavaria (1276–1345).