2021 Uruguayan Segunda División season

The 2021 Uruguayan Segunda División was the season of second division professional of football in Uruguay. A total of 12 teams competed; the top two teams and the winner of the Championship play-offs were promoted to the Uruguayan Primera División. On 19 March 2021, Nicolás Siri became the youngest hat-trick scorer in the history of Uruguayan football and the second in South America behind Pelé, after scoring a hat-trick in Danubio's 5–1 win against Boston River, at the age of 16 years and 11 months.

Second leg

 * Racing and Defensor Sporting advanced to the Finals due to having a better campaign.

Finals
Defensor Sporting won 3–0 on aggregate and were promoted to Primera División.

Relegation playoffs
''Tied 3–3 on aggregate. La Luz won on penalties and were promoted to Segunda División.''