After a short stint in junior rugby league , Koroibete signed a 3-year contract with the Wests Tigers to play in Australia, initially in the Toyota Cup national under-20 competition.

[7] In just his second game in Round 22, Koroibete scored 4 tries for the Tigers against the 51-26 win Parramatta Eels at Campbelltown Stadium, equaling the club record for most tries in a match set by Kevin McGuinness ten years earlier.

[10] Koroibete was also named the joint Rookie of the Year for the Wests Tigers,[11] and one of the top ten upcoming youngsters in the NRL in Lifestyle Uncut Magazine.

[13] In February, Koroibete was included in the Wests Tigers inaugural 2014 Auckland Nines squad, despite having a problem with his visa to gain entry into New Zealand.

[22] Koriobete accepted a contract offer to join Super Rugby side the Melbourne Rebels for the 2017 season.

The offer allowed him to play for the Rebels as well as for the Australia national team, for whom he had already qualified under the four-year residency rule.

[27][28] In October 2016, just weeks after playing in the 2016 NRL Grand Final, Koroibete was named in the Wallabies squad for their end-of-year tour to Europe.

[32] Koroibete would make history by becoming the first winger to win the John Eales Medal in 2019, scoring a Wallabies-high seven tries this year and producing standout performances at the Rugby World Cup.

[citation needed] Koroibete won his second John Eales Medal in 2022, holding off Len Ikitau and Allan Alaalatoa.