The Fiji Broadcasting Corporation said Rabeni, who played club rugby with the Otago Highlanders in New Zealand before switching to England’s Leicester Tigers, died at home in Nakasi.
It did not give a cause of death.
Rabeni represented his country 30 times, playing at the 2003 and 2007 World Cups and also featured on the World Sevens Series and at the 2002 Commonwealth Games.
Australia winger Lote Tuqiri, who was born in Fiji, said on Twitter: “Man just heard the news of Fijian and @LeicesterTigers legend Seru Rabeni passing this morning in Fiji. A great man taken way too young @ 37”.