Guy of Thouars

Guy of Thouars (died 13 April 1213) was a noble of the House of Thouars and the third husband of Constance, Duchess of Brittany, whom he married in 1199. He ruled as duke until Constance died giving birth to twin daughters in 1201. After her son Arthur I disappeared in English captivity in 1203, Guy served as regent for his own daughter Alix until 1206.

In 1204 he besieged and burned Mont Saint-Michel. In 1206 Philip II of France took the regency himself. Guy died at Chemillé in 1213 and was buried beside Constance at Villeneuve Abbey.