István Bánffy de Losoncz was born 11 October 1962 in Cluj-Napoca, Cluj County, Romania to Béla Bánffy de Losoncz (1936) and Márta Gálffy de Mészkő (1940) . He married Aranka Simon (c1965) February 1986 in Cluj-Napoca, Cluj County, Romania.
Children
| Name | Birth | Death | Joined with |
| Endre Bánffy de Losoncz (1986) | 1986 Cluj-Napoca, Cluj County, Romania | ||
| Árpad Bánffy de Losoncz (1989) | 1989 | ||
| Tamás Bánffy de Losoncz (1996) | 1996 | ||
| Eszter Bánffy de Losoncz (1998) | 1998 | ||
Siblings
| Name | Birth | Death | Joined with |
| István Bánffy de Losoncz (1962) | 11 October 1962 Cluj-Napoca, Cluj County, Romania | Aranka Simon (c1965) | |
| Márta Bánffy de Losoncz (1965) | 7 March 1965 Cluj-Napoca, Cluj County, Romania | István Pázmány (c1962) | |
| Béla Bánffy de Losoncz (1968) | 1 December 1968 Cluj-Napoca, Cluj County, Romania | Nomen nescio | |
Residences
Footnotes (including sources)