The Belgium central defender moved to White Hart Lane in July 2012 from Dutch side Ajax.
The Belgium central defender moved to White Hart Lane in July 2012 from Dutch side Ajax and has since become a mainstay of manager Mauricio Pochettino's team.
"I was very happy once I put my autograph on the paper," Vertonghen told Spurs TV, the club's in-house broadcast channel.
"I was extremely happy, big relief. I'm very happy to be here, the future looks great so I am very happy to be a part of it," added Vertonghen, who has so far made 179 appearances for Tottenham.
His partnership at the back with Toby Alderweireld last season fuelled Spurs' title challenge, with the club qualifying for the Champions after conceding just 35 Premier League goals -- the joint-lowest total in English football's top flight.
Vertonghen has followed the lead of several Spurs team-mates, including Harry Kane, Kyle Walker, Christian Eriksen, Eric Dier, Danny Rose and Dele Alli in extending his contract.
His decision came just 24 hours after Kane signed on with Spurs until 2022 and Vertonghen said: "This is an unbelievable group of talented guys and I feel privileged to be a part of that. There's a great atmosphere in the team and a great buzz around Tottenham.
"It feels great to be a little part of the big part Tottenham is. I can't imagine playing somewhere else at the moment," added the 29-year-old Vertonghen, now into his fifth season at Tottenham since moving from Dutch giants Ajax.
"This is probably the strongest squad I've ever played in and I think everyone agrees with me."