Orri Óskarsson came through the academy of Grótta, in his native Iceland. He made his senior debut with the club on 18 August 2018, aged 13 years and 354 days, when he came on as a substitute in the 2018 2. deild match against Höttur, scoring two goals on his debut in a 5–0 victory.[1][2] In total he played 3 games and scored 3 goals in his first season as the club were promoted from the third tier under the management of his father, Óskar Hrafn Þorvaldsson.[1][3] He played 12 games out of 22 and scored 1 goal in the following season in the second tier, as Grótta were promoted again, this time to the top tier.[3][4]
Copenhagen
After the 2019 season, it was announced that Orri would be joining the Danish club FC Copenhagen in the summer of 2020.[1][5] He made his professional debut for Copenhagen on the 22 May 2022, during the last game of that season—a 3–0 home league win against Aalborg BK, only few days before he signed a contract extension with the Danish champions.[6][7]
His father is former international footballer and current manager of FK Haugesund, Óskar Hrafn Þorvaldsson. His father managed him while he played with Grótta in both the youth teams and the first team.[1]