Klaas Jong was born 1837 in Lutjebroek, North Holland, Netherlands to Joannes Jong (1798-1859) and Trijntje Bakker (1799-1891) and died 7 April 1904 Grootebroek, North Holland, Netherlands of unspecified causes. He married Carolina Steltenpohl (1833-1903) 16 January 1862 in Grootebroek, North Holland, Netherlands.
Children
| Name | Birth | Death | Joined with |
| Petrus Jong (c1871-1853) | |||
Siblings
| Name | Birth | Death | Joined with |
| Geertje Jong (1826-1898) | |||
| Lijsebeth Jong (1826-1883) | 29 August 1826 Lutjebroek, North Holland, Netherlands | 9 June 1883 Grootebroek, North Holland, Netherlands | Paulus Groot (1822-1885) |
| Paulus Jong (1830-1909) | |||
| Cornelis Jong (1832-1908) | |||
| Klaas Jong (1837-1904) | 1837 Lutjebroek, North Holland, Netherlands | 7 April 1904 Grootebroek, North Holland, Netherlands | Carolina Steltenpohl (1833-1903) |
| Pieter Jong (1842-1867) | 24 February 1842 Lutjebroek, North Holland, Netherlands | 13 October 1867 Montelibretti, Lazio, Italy | |