Gijsbrecht III was born on an unknown date to Gijsbrecht II van Amstel (c1170-c1228) . He married Unknown van Cuijk (bef1210-c1250) .
Children
| Name | Birth | Death | Joined with |
| Arnold Arend van Amstel (c1230-c1291) | |||
| Gijsbrecht IV van Amstel (c125-c1303) | 1235 | 1303 | Badeloch van Woerden |
| Willem van Amstel (c1236-23-05 1292) | |||
| Elizabeth (Badeloch) van Amstel (c1240-1296) | |||