Matilda of Brandenburg (c. 1210 – 10 June 1261) was a daughter of Albert II, Margrave of Brandenburg, and Matilda of Lusatia. In 1228 she married Otto I, Duke of Brunswick-Lüneburg, a son of William of Winchester. She died on 10 June 1261 in Lüneburg. Mathilde and Otto had the following known children:
- Elizabeth (died 1266), married William II of Holland
- Helen (died 1273), married Albert I, Duke of Saxony and Hermann II, Landgrave of Thuringia
- Adelaide (died 1274), married Henry I, Landgrave of Hesse
- Matilda (died around 1295), married Henry II, Prince of Anhalt-Aschersleben
- Agnes, married Wizlaw II, Duke of Rügen
- Albert (died 1279)
- John (died 1277)
- Otto, Bishop of Hildesheim (died 1279)
- Conrad, Prince-Bishop of Verden (died 1300)