Hansen-Aarøen played for Tromsø's first-team at the age of 15, in the second-tier of Norwegian football, before joining Manchester United's youth system in 2020.
[2] In 2019, Hansen-Aarøen won the under-15 Talent of the Year award in a contest organised by the Norwegian Football Federation, TV 2 and Equinor's Heroes of Tomorrow initiative.
[3] He made his senior debut for Tromsø on 6 July 2020, replacing Kent-Are Antonsen for the last minutes of a 2–0 win at Kongsvinger in a Norwegian 1. divisjon match.
[13] He made his Bundesliga debut on 30 March 2024, coming on as a substitute for Skelly Alvero after 79 minutes in a 2–0 loss against VfL Wolfsburg.
[15] In December 2024, after Hansen-Aarøen had not featured in the Bundesliga while scoring one goal in two Regionalliga Nord appearances for Werder Bremen's reserves, it was announced he would join Danish Superliga club Aalborg BK on loan for the second half of the season.