Caleb Muntz was born in Huntly, New Zealand to a Maori mother and a father of Fijian and European descent.
He later made his debut for Fiji against Tonga in Lautoka on 22 July 2023, scoring 9 points (1 penalty, 3 conversions).
[7] On 8 August 2023, he was named in the final group of 33 players selected by Simon Raiwalui to participate in the World Cup in France.
[8] Shortly thereafter, in only his fourth match, Muntz was part of the Fijian team that beat England for the very first time on 26 August 2023 at Twickenham.
[9] In November 2024, Muntz scored a try, a conversion and four penalties in Fiji's 24-19 win over Wales in the 2024 Autumn Nations Series.