István Ilosvay was born circa 1482 in Hungary to László Ilosvay (1458-1530) and died 1530 Hungary of unspecified causes.
Children
| Offspring of István Ilosvay and Nomen nescio | |||
| Name | Birth | Death | Joined with |
| András Ilosvay (1503-1552) | |||
| Jakab Ilosvay (1505-1528) | |||
| Ilosvay Péter (1505-1518) | |||
| Offspring of István Ilosvay and Hedvig Dolhay (c1505-c1550) | |||
| Name | Birth | Death | Joined with |
| Ferencz Ilosvay (1523-1551) | |||
| Anna Ilosvay (c1525-c1565) | |||
| István Ilosvay (1528-1547) | |||
