[1] His father, Paul Ontong, was born in South Africa and played in the NSL for Canberra City, Mooroolbark SC and Brisbane Lions.

[2][3] Ontong grew up in Canberra, playing junior football for local clubs Belwest Foxes and later Belconnen United.

FC Nürnberg,[5] but suffered a groin injury during the trial and returned to Australia.

[6] He spent time briefly with Melbourne Victory before heading back to Europe, trialling with FC Sion and later in Slovenia with NK Maribor and Bela Krajina, but his recurrent injury forced another return home.

Ontong received 10 caps at international U20 level and captained the Young Socceroos through the AFC Youth Championship 2006 campaign.