2021–22 Scottish League One

The 2021–22 Scottish League One (known as cinch League One for sponsorship reasons) was the ninth season of Scottish League One, the third tier of Scottish football. The season began on 31 July.

Ten teams contested the league: Airdrieonians, Alloa Athletic, Clyde, Cove Rangers, Dumbarton, East Fife, Falkirk, Montrose, Peterhead and Queen's Park.

Teams
The following teams changed division after the 2020–21 season.

To League One
Promoted from League Two
 * Queen's Park

Relegated from the Championship
 * Alloa Athletic

From League One
Relegated to League Two
 * Forfar Athletic

Promoted to the Championship
 * Partick Thistle

Matches 1–18
Teams play each other twice, once at home and once away.

Matches 19–36
Teams play each other twice, once at home and once away.

League One play-offs
The semi-finals were contested by the teams placed second to fourth in Scottish League Two, as well as the team placed ninth in Scottish League One. The winners advanced to the final, with the highest-ranked team hosting the second leg.