Welf III (died 13 November 1055), as he is numbered in the genealogy of the Swabian line of the Elder House of Welf, was the duke of Carinthia and margrave of Verona from 1047. He was the only son of Welf II, Count of Altdorf, and Imiza.
Carinthia was the last German duchy to be held personally by the Emperor Henry III before he gave it to Welf. Welf III never married and had no children when he died at his castle on Lake Constance in 1055. He bequeathed his property to the monastery of Altdorf, where his mother was abbess. She in turn gave the property to Welf IV, the son of Welf III's sister Chuniza and Albert Azzo II, Margrave of Milan. Welf was the last of the Elder Welfs, his lands went to the senior branch of the House of Este, which is called the Younger House of Welf. His duchy went to Conrad III.
| Preceded by Henry IV |
Duke of Carinthia 1047–1055 |
Succeeded by Conrad III |