| Isabelle de Meulan | |
| Dame de Mayenne Dame de Craon | |
| Spouse: | Geoffroy, Seigneur de Mayenne Maurice II, Sire de Craon |
| Issue: | Clémence de Mayenne Juhel III, Seigneur de Mayenne Avoise de Craon Maurice III, Sire de Craon Pierre de Craon Philippe de Craon Amaury I, Sire de Craon Constance de Craon Agnes de Craon |
| Birth Date: | c. 1148 |
| Death Date: | 10 May 1220 |
| Death Place: | France |
| Father: | Waleran de Beaumont, 1st Earl of Worcester, Count of Meulan |
| Mother: | Agnès de Montfort, Dame de Gournay-sur-Marne |
| Noble Family: | House of Beaumont |
Isabelle de Meulan, Dame de Mayenne, Dame de Craon (c. 1148 – 10 May 1220) was a French noblewoman, being the daughter of Waleran de Beaumont, 1st Earl of Worcester, Count of Meulan. Isabelle married twice; firstly to Geoffroy, Seigneur de Mayenne, and secondly to Maurice II, Sire de Craon. Her eldest son was a celebrated Crusader.
Isabelle was born in about 1148, the eldest daughter of Waleran de Beaumont, 1st Earl of Worcester, Count of Meulan, and Agnès de Montfort, Dame de Gournay-sur-Marne. She had six brothers and two younger sisters. Her father was a powerful Norman magnate with much wealth and political influence. Her paternal grandparents were Robert de Beaumont, 1st Earl of Leicester and Elisabeth de Vermandois, and her maternal grandparents were Amaury III de Montfort, Count of Evreux, and Agnès de Garlande, daughter of Anseau de Garlande, Count of Rochefort, and Beatrice de Montlhery.
In 1161 Isabelle married her first husband, Geoffroy, Seigneur de Mayenne whose first wife Constance of Brittany had died in 1148. Together Geoffroy and Isabelle had:
Geoffroy died in 1169. Isabelle, aged about twenty-two, married secondly in 1170 Maurice II, Sire de Craon, the son of Hugues I, Sire de Craon. Together they had seven children:
Isabelle was appointed guardian of Maurice's lands and their children when he left for Jerusalem on Crusade. The Gesta Guillelm Majoris Andegavensis Episcopi names Isabelle among those present at the burial of the Bishop Guillaume on an unknown date during the reign of King Philip II of France.Her husband died 12 July 1196. Isabelle herself died on 10 May 1220 at the age of about seventy-two years. Her death occurred just a month after the death in battle of her eldest son, Juhel. She was buried in Savigny.
. The Beaumont Twins: The Roots and Branches of Power in the Twelfth Century . registration . David Crouch (historian) . Cambridge University Press . 1986 .