George III of Brieg (Polish: Jerzy III Brzeski; Brzeg, 4 September 1611 – Brzeg, 4 July 1664), was a Duke of Brzeg since 1633 (as administrator; in 1639 he took formally the title, together with his brothers until 1654) and Legnica-Wolów during 1653-1654 (with his brothers).
He was the eldest son of John Christian, Duke of Brzeg-Legnica-Wolów-Olawa, by his first wife Dorothea Sybille, daughter of John George, Elector of Brandenburg.