Manchester United Youth

Manchester United Football Club Under-21s is the most senior of Manchester United's youth teams and the club's former reserve team. They play in the Premier League 2, the highest tier of the Professional Development League. The team is effectively Manchester United's second-string side, but is limited to five outfield players and one goalkeeper over the age of 21 per game following the introduction of new regulations from the 2022–23 season, a change from three outfield players over age 23 introduced in 2016–17. The age limit previously was again 21, from 2012–13. The team's current manager is Travis Binnion, who took over from Mark Dempsey in 2023.

They were champions of the former Premier Reserve League five times (in 2002, 2005, 2006, 2010 and 2012) between its introduction in 1999 and its dissolution in 2012. The team also won the 2012–13 Professional U21 Development League 1 in its inaugural season, and again in 2015 and 2016. The team also participates in the regional Manchester Senior Cup and the Lancashire Senior Cup. From the 2019–20 edition, they also participate in the nationwide EFL Trophy along with senior teams from levels 3 and 4 of the English football league system, as teams from levels 1 and 2 are restricted to players aged 21 and under.