Countess Margaret of Luxembourg (c. 1340–1410) was a noblewoman from the House of Luxembourg. She was the daughter of John of Luxembourg, King of Bohemia, and Elisabeth of Bohemia. Margaret married John III of Brabant, strengthening political ties between their regions. Margaret played a significant role in the governance of Brabant and Limburg during her husband's absence. She was known for her intelligence and leadership, managing the affairs of her territories effectively. Her legacy includes contributions to the cultural and political landscape of the Low Countries during the late medieval period.