Following his switch to rugby union, he made his international debut against Ireland in Perth in June 2003 (which the home side won 45-16) and immediately made an impact, being Australia's star player at the Rugby World Cup where he scored a try in the final against England.
He continued to play for the NSW Waratahs and Australia between 2003 and 2008, including another World Cup in France in 2007. In all he made 67 appearances for the Wallabies, of which four caps came against Ireland.
Lote then left Australian rugby for a season with the Leicester Tigers in England where he excelled before the West Tigers lured him back to rugby league and he fulfilled his dream of again playing for the Kangaroos on his return.
Commenting on the deal, Leinster head coach Matt O'Connor said: "We are delighted to welcome a player of Lote's calibre and his enthusiasm to make a positive impression at Leinster is exciting for both his new team-mates and supporters alike.
"A consummate professional, Lote has an enormous wealth of experience in the game and we believe that he will play an important role in the squad over the coming weeks."