Vertonghen, who has played 179 games for Spurs since joining in 2012, was in commanding form alongside compatriot Toby Alderweireld at the heart of a defence that conceded just 35 league goals last season.
"We are delighted to announce that Jan Vertonghen has signed a new contract with the Club, which will run until 2019," Spurs said on their website (www.tottenhamhotspur.com).
The 29-year-old Vertonghen, who has made 17 appearances this season, joins Harry Kane, Dele Alli, Eric Dier, Kyle Walker, Christian Eriksen and Danny Rose in committing his long-term future to the north London club in recent months.
Fifth-placed Tottenham, seven points off top spot after 13 games, host second-bottom Swansea City on Saturday having lost their unbeaten league record at Chelsea last weekend. (Reporting by Shravanth Vijayakumar in Bengaluru; editing by Ken Ferris)