Olivier III de Clisson (1280–1320), was a Breton Marche Lord and knight.

[1][2] Olivier III continued expanding the de Clisson influence outside Brittany and in 1299, married Isabeau de Craon (1278 - July 30, 1350), daughter of Maurice VI de Craon.

The Lords of Craon were mainly Norman with a history as former adversaries of the Dukes of Brittany.

[3][4] This Olivier III was now also son and heir of Jeanne Bertran, lady of Tuit, eldest daughter of Guillaume Bertran, lord of Tuit and Thury, a rich Norman heritage.

[5][6] Olivier III and Isabeau would eventually have five children: