Frederick III (ca. 1020 – 1033) was the Count of Bar and Duke of Upper Lorraine from the death of his father, Frederick II, in 1026 or 1027 to his own death. His mother was Matilda, daughter of Herman II, Duke of Swabia.
His father had been co-duke since 1019 and his grandfather, Thierry I, continued to reign until his own death in 1027 or 1028. His reign is completely obscure. Even his regent is unknown. He died young and his county passed to his sister Sophia while Lorraine was given to Gothelo I, Duke of Lower Lorraine.
| Preceded by Frederick II |
Duke of Upper Lorraine 1026–1033 |
Succeeded by Gothelo |