The Sheffield Wednesday U21s are the reserve team of Sheffield Wednesday Football Club, who play in the Championship, the second tier of English football. The team was formed in 2005, following the withdrawal of the Sunday Amateur club from the League of Wales. As a result, the Wednesday reserve side played their first ever game on 6 August 2005, a 2–0 victory over Northwich Victoria at Greenheys.
The Wednesday reserves have enjoyed mixed fortunes since their inception, winning the Northern Premier League title in 2007 and 2008 whilst being relegated in 2009 and 2010, only to return to the Premier Division in 2011. In 2012, they were relegated again, this time to Division One North. However, the following season they won the division and returned to the Championship.
The Wednesday reserve team plays its home games at Prenton Park, the home of Preston North End, and currently has a squad of 27 players.