Ulrich III, Duke of Carinthia

Ulrich III of Spanheim
Duke of Carinthia
Part of a seal used by Ulrich III
Duke	1256–1269
Predecessor	Bernhard von Spanheim
Successor	Ottokar II of Bohemia
Spouse(s)	Agnes of Andechs Agnes of Baden
Noble family	House of Sponheim
Father	Bernhard von Spanheim
Mother	Judith of Bohemia
Born	c. 1220
Died	27 October 1269(1269-10-27) Cividale del Friuli

Ulrich III, Duke of Carinthia, also known as Ulrich III of Spanheim (c. 1220 – 27 October 1269) was ruling Lord in the March of Carniola from c. 1249 and Duke of Carinthia from 1256 until his death, the last ruler from the House of Sponheim.

Ulrich III was the eldest son of Duke Bernhard of Carinthia and his wife Judith, a daughter of the Přemyslid king Ottokar I of Bohemia. Already his father had endeavoured to assume the rule over the Carniolan march, which Ulrich could secure for himself by marrying Agnes of Andechs, the widow of the last Babenberg duke Frederick II of Austria. From 1251, he was co-ruler of Carinthia with his father; in 1256 he succeeded his father as duke.

Ulrich continued the development of his home territories as his father began. In 1260, he completed the foundation of the charterhouse in Bistra (Freudenthal) in Inner Carniola. He also founded the Canons Regular monastery in Völkermarkt.

He had differences of opinion about his father's inheritance with his younger brother Philip, who had to prepare for an ecclesiastical career and was elected Archbishop of Salzburg in 1247. Philip refused to take holy orders in order to reserve the right of succession in Carinthia for himself. Ulrich and Philip finally reached an agreement of mutual protection and inheritance and, after Philip was deposed as bishop in 1257 by the cathedral chapter, fought together against Philip's successor, Archbishop Ulrich of Seckau.