Siaosi Nginingini was born and raised in Tonga.

Nginingini played rugby for Falaleu RFC in Tonga and went through the Counties Manukau Academy where he was part of the Under 19 team and played for the senior side in 2019.

In 2021, Nginingini joined the North Harbour’s NPC set up and was named in their full squad for the 2024 season.

The nifty halfback was named in Moana Pasifika’s development team for the 2024 and 2025 season. He made his Super Rugby debut for Moana Pasifika against the Chiefs in Round Twelve of the 2024 season.

In November 2024 Nginingini made his international debut for the ‘Ikale Tahi against Romania and scored his first try against the United States.

Moana Pasifika debut: 2024 v Chiefs