Gertrude of Flanders (1135–1186) was a Countess Consort of Savoy.
She was the daughter of Thierry, Count of Flanders, and his second wife Sibylla of Anjou. In 1155, she married Humbert III, Count of Savoy, but he divorced and confined her in 1163. She was freed thanks to Robert, bishop of Cambrai, and returned to the court of her brother, Philip of Flanders. She remarried Hughues d'Oisy, but the marriage was annulled, and she retired to a convent.