Caulker, 20, impressed on loan at Swansea City last season and Spurs have signalled their optimism over his future by rewarding him with a new deal.
The centre-back emerged from the Tottenham academy and has spent successive loan spells at Yeovil, Bristol City and Swansea over the past three seasons.
Swansea hoped to re-sign him for the 2012-13 Premier League season but chairman Huw Jenkins said earlier on Thursday that was unlikely.
Caulker is a regular for England at Under-21 level and was this week named in the Great Britain squad for the London 2012 Games.
News of his contract comes in a week when Spurs have appointed Andre Villas-Boas as their new manager and signed midfielder Gylfi Sigurdsson, who last season played alongside Caulker at Swansea.