Bertha of Blois (French: Berthe de Blois; c. 1005 — c. 1080), was a Duchess consort of Brittany and a countess consort of Maine, married in 1018 to Alain III, Duke of Brittany, and in 1046 to Hugh IV, Count of Maine. She was the daughter of Odo II, Count of Blois and Ermengarde of Auvergne.
- K. S. B. Keats-Rohan, Two Studies in Northern French Prosopography, Journal of Medieval History 20 (1994). p. 22.
- Detlev Schwennicke. Europäische Stammtafeln: Stammtafeln zur Geschichte der Europäischen Staaten.
Hawise of Normandy
| Duchess consort of Brittany
Constance of Normandy
| Countess consort of Maine
Eria of Hauteville