Alderweireld’s previous deal was due to expire at the end of this season, and he would have been free to talk to foreign clubs from January.
The former Ajax Amsterdam defender’s new deal will reportedly triple his weekly earnings from £50,000 to £150,000.
Together with Christian Eriksen and Jan Vertonghen, Alderweireld was one of three key Tottenham players whose contracts were expiring next summer, and were seemingly on their way out but the arrival of Jose Mourinho has led to a change of heart.
A club statement read: "We are delighted to announce that Toby Alderweireld has signed a new contract with the club until 2023."
Speaking to Spurs TV after putting pen to paper, Alderweireld said: 'I'm very, very happy, no words can describe. Another couple of years at Spurs, there's no place I'd be happier.
'I'm honoured to play for this club. I'm a small piece of getting to the next level in a couple of seasons, reaching the Champions League season in and season out and then reaching the final.
'This is just the beginning of something big and something very exciting.
'If you're happy and enjoying yourself, time flies. My family is happy here and I'm very lucky to have a very good connection with the fans.
'I'm a Spurs player and I couldn't see myself playing for another team. I'm in love with the club and it feels both ways, I love the fans and the stadium. I'm living some sort of dream.'
The 30-year-old joined Tottenham from Atletico Madrid in the summer of 2015 and has 179 appearances during his time at the club.
He helped Tottenham to their first Champions League final last term and has made 20 appearances in all competitions already this season.
