Uruguay international Bentancur joined Spurs at the start of 2022 from Juventus and has gone on to make 122 appearances for the Premier League club – including starting their Europa League final triumph in May.
The 28-year-old had entered the final 12 months of his previous deal but has committed his long-term future to Tottenham under new boss Thomas Frank.
Bentancur told the official club website: “I feel really good and I’m very happy to continue my story with this fantastic club.
“My family are happy; I have fantastic friends and team-mates who work hard every day. I love this club and feel really good here.
“Winning the Europa League was a fantastic moment and we want to build on this now, to win more trophies.
“We have a new head coach, a new captain (Cristian Romero) and I want to enjoy many more years at the club.”