After his selection to the Avalanche in the first round, 28th overall, in the 2021 NHL entry draft, Olausson was originally slated to return to newly relegated HV71 of the Allsvenskan.
[3] With his previous selection of his junior rights in the CHL Import Draft going to the Barrie Colts, 118th overall, Olausson agreed to terms with the club, giving a commitment on 20 August 2021.
Following a first-round exit in the post-season, Olausson was re-assigned by the Avalanche to join primary affiliate, the Colorado Eagles of the AHL, for the playoffs on 2 May 2022.
[7] After posting 8 points through 16 games for the Eagles and with the Avalanche dealing with a glut of injuries, Olausson received his first NHL recall on 23 November 2022.
[8] Initially placed on the Avalanche's second-line, Olausson made his NHL debut that night at Ball Arena in a 4–3 defeat to the Vancouver Canucks.