Sir John de Grey of Codnor was born circa 1225 in England to Richard de Grey (c1195-c1250) and Lucy de Humes (-c1250) and died 5 January 1271 England of unspecified causes. He married Lucy de Mohun (c1227-1272) .
Children
| Name | Birth | Death | Joined with |
| Henry de Grey, 1st Baron Grey of Codnor (c1260-1308) | 1260 England | September 1308 England | Eleanor Courtenay (c1263-1301) |
| Andrew de Grey (-1300) | |||
Siblings
| Name | Birth | Death | Joined with |
| Agnes de Grey (-c1295) | |||
| John de Grey (c1225-1271) | 1225 England | 5 January 1271 England | Lucy de Mohun (c1227-1272) |