John Wong was born as the 7th of 11 children (five brothers and five sisters) on 6 June 1968 in Sandakan, Sabah to ethnic Hakka Chinese Catholic parents.

His father, Paul Wong Shui Tshun was a hawker selling yong taufu (stuffed bean curd) and fish balls at the Sandakan Central Market, while his mother, Rose Chung Thiem Yin (born 1939) was a housewife.

The late Fr Tobias Chi, the then parish rector of the church in Sandakan, had much influence in his consideration of the priestly vocation, whilst being present during his ordinations.

Among the unopened mail he brought along was a letter with a Bangkok post mark, the city where the office of the Apostolic Nuncio of Pope Benedict XVI was located.

He is the current President of the Catholic Bishops' Conference of Malaysia, Singapore and Brunei Episcopal Regional Commission for Family, Laity and Life.

In his tenure as shepherd, he launched the Kadazan Audible Bible together with the former Apostolic Nuncio to Malaysia, Most Rev Joseph Marino, at Holy Family Church, Telipok, in 2016.