[2] He grew up in Hokianga alongside James Fisher-Harris before moving down to Auckland to play his junior rugby league for Otaua Valley Warriors.

[3][4] In 2014 and 2015, Harawira-Naera played for the Penrith Panthers in the National Youth Competition,[5] before graduating to their Intrust Super Premiership NSW team in 2016.

[10] Harawira-Naera would show good form during the season and became a mainstay in the top 17 with coach Anthony Griffin opting to start him at second-row in most matches over Bryce Cartwright and James Fisher-Harris.

Canterbury CEO Andrew Hill said: "Signing someone of Corey’s calibre and potential is a great coup for Canterbury and comes on the back of a strong finish to our 2018 season", "Dean Pay and his coaching staff have helped develop some talented young players this year and the addition of Corey to the squad will add both quality and strength to our forward pack for next season and beyond".

During the Panthers presentation night, chairman Phil Gould said he personally recruited Harawira-Naera from New Zealand, as he fought back tears as he spoke about the hard-hitting forward.

[16] In Round 1 of the 2019 NRL season, Harawira-Naera made his club debut for the Canterbury-Bankstown Bulldogs against the New Zealand Warriors, playing off the interchange bench in the 40–6 loss at Mt Smart Stadium.

[22] He made a total of 15 appearances for Canberra in the 2021 NRL season as the club finished 10th on the table after many had expected them to reach the finals and challenge for the premiership.

[26] Harawira-Naera played a total of nine matches for Canberra in the 2023 NRL season as the club finished 8th on the table and qualified for the finals.

[30] denotes season still competing [31] On 10 March 2020, Harawira-Naera and teammate Jayden Okunbor were stood down by Canterbury two days before the start of the 2020 NRL season after it was alleged that while on a pre-season trip to Port Macquarie earlier in March they brought two teenage schoolgirls to the team hotel where sexual activity may have taken place.

Canterbury released a statement saying "The NRL have today deregistered both Jayden Okunbor and Corey Harawira-Naera with immediate effect and as a result their playing contracts with the Bulldogs have been cancelled, The conduct of the two players, on the eve of our final trial match, demonstrated an unacceptable lack of respect for their teammates, their coach and club officials, our hosts in Port Macquarie and fans of the game everywhere".

Jayden Okunbor was retrospectively given a 14 game ban (from the date of contract termination), a $22,500 fine and a course of counselling / community service.

[37] Upon winning his appeal, Harawira-Naaera asked the Canterbury club for a release and signed a 2.5 year contract with the Canberra Raiders.