Joan of Châtillon (d. 1292), was countess of Blois from 1280 to 1292, and lady of Avesnes. She was the daughter of John I and Alix of Brittany. Her maternal grandparents were John I, Duke of Brittany and Blanche of Navarre. In 1263, Joanne married Pierre of Alençon, son of Louis IX of France and Marguerite of Provence. They had 2 children who died young. Pierre died in 1283. Joan received the County of Chartres from her father during his life; she later sold these lands to Philip IV of France in 1291. She ceded the lordship of Avesnes to her cousin Hugh before her death. When she died in 1292 the other titles were left to him, too.
| Preceded by John I |
Countess of Blois 1280–1292 |
Succeeded by Hugh II |
| Countess of Chartres bef. 1278–1280 |
Succeeded by merged with Blois; to royal domain 1291 |
