Pochettino announced almost two weeks ago he had struck a verbal agreement with Spurs and the deal has now been officially confirmed.
The 44-year-old was appointed in May 2014 and has achieved remarkable progress at White Hart Lane, leading Tottenham to second place this season with one game left to play.
Assistant head coach Jesus Perez, first-team coach Miguel D'Agostino and goalkeeping coach Toni Jimenez have also agreed contract extensions.
Pochettino said: "I could not be happier to sign this new contract.
"It was an easy decision for my coaching staff and I because we can feel the appreciation of everyone here. There is no better place to be right now.
"We have enjoyed a great season and we believe this is just the beginning."
Tottenham's title challenge ended with a draw at Chelsea earlier this month but the team are guaranteed second place if they beat Newcastle on Sunday.
It would be the club's highest top-flight finish since 1963 and would ensure Spurs ended a season above north London rivals Arsenal for the first time since 1995.
Tottenham chairman Daniel Levy said: "We've seen Mauricio bring a tremendous spirit and ethos to our club and embrace the attacking style of play with which we have always been associated.
"He's built a squad of youth and experience and this season we've seen football played at the highest level - quite sublime at times.
"Everyone at the club is delighted he has agreed an extended contract and we all look forward to working with him in the coming seasons. I know he is as ambitious for our club as we are."
Source: PA