2021 Lillestrøm SK season

The 2021 season was Lillestrøm SK's 104th season in existence and the club's first season back in the top flight of Norwegian football. In addition to the domestic league, Lillestrøm SK participated in this season's edition of the Norwegian Football Cup.

Winter
In:

Out:

Summer
In:

Out:

Norwegian Cup
Fourth round took place during the 2022 season.