Ong is the son of
Ong Tiang Swee (1864-1950), renowned businessman and the most prominent and successful Chinese community leader in Sarawak. Generations of the Ong family played a prominent role for the Hokkien community in Sarawak. His grandfather,
Ong Ewe Hai was a prominent Kapitan Cina to the Hokkien community of Sarawak, and a successful businessman in multiple fields. His father,
Ong Tiang Swee also succeeded him as Kapitan Cina. Both Ong Tiang Swee and Ong Kwan Hin were the first two Chinese people nominated to the Sarawak Council Negri (Legislative Council) in 1937. His son,
Ong Kee Hui, also went into business and subsequently public service, where he co-founded the
Sarawak United People's Party (SUPP),
Sarawak's first political party in 1959. Kee Hui later served as the Minister of Local Government and Housing, and established the Ministry of Science Technology & Environment under Tun Razak's Cabinet, serving as a Federal Minister. == Early life ==