Southampton U21

Southampton F.C. B team and Academy or Saints B and Academy is the youth organisation run by Southampton F.C. to encourage and develop young footballers in the south of England. Renowned players including Gareth Bale, Theo Walcott, and Alan Shearer began their careers at this academy. The team is made up of under-23 and academy players, is effectively Southampton's second-string side, but is limited to three outfield players and one goalkeeper over the age of 23 per game following the introduction of new regulations from the 2012–13 season. They play in Premier League 2, Division 1. The team also competes in the EFL Trophy, Premier League International Cup, Premier League Cup and the Hampshire Senior Cup. The under-18 players among other younger age groups make up the Academy team and play in the Premier League U18 First Division, South, Premier League U18 Cup and the FA Youth Cup.

Home fixtures are contested at A.F.C. Totton's Testwood Stadium with some fixtures being held at St. Mary's. Some games are played at the club's training facilities at Staplewood in Long Lane, Marchwood, Southampton if required.. Since Septeember 2020, the B team has been managed by David Horseman, with Paul Hardyman managing the under-18 side.