Richilde | |
|---|---|
| Countess of Mons and Hainaut Margravine of Valenciennes | |
 Richilde, Countess of Mons and Hainaut, Margravine of Valenciennes | |
| Born | c. 1018 |
| Died | 15 March 1086 Mesen |
| Spouse(s) | Herman of Mons Baldwin VI, Count of Flanders William FitzOsbern, 1st Earl of Hereford |
| Father | Reinier of Hasnon |
| Mother | Adelheid of Egisheim |
Richilde, Countess of Mons and Hainaut (c. 1018 – 15 March 1086), was a ruling countess of Hainaut from c. 1050 until 1076, in co-regency with her husband Baldwin VI of Flanders (until 1070) and then her son Baldwin II of Hainaut. She was also countess of Flanders by marriage to Baldwin VI between from 1067 to 1070. She ruled Flanders as regent during the minority of her son Arnulf III in 1070–1071.