Both players were due to leave the north Londoners on June 30, but the recent agreement means they will be available to play in all of Spurs' eight remaining Premier League matches.
Meanwhile, a host of players out on loan will also stay at their respective clubs, including Danny Rose at Newcastle.
A Tottenham statement read: "We can confirm that defender Jan Vertonghen and goalkeeper Michel Vorm have agreed to extend their existing contracts with the club until the end of the 2019/20 season.
"Both players' contracts were due to expire at the end of this month and this extension means they will now be available to play for us for the remainder of the current Premier League season.
"We have also agreed to extend the loans of Danny Rose (Newcastle United), Kyle Walker-Peters (Southampton), Jack Clarke and Luke Amos (both QPR), Brandon Austin (Viborg) and Armando Shashoua (Atletico Baleares) until the end of their respective league seasons."
Spurs played out a 1-1 draw with Manchester United last Friday as the Premier League returned from its coronavirus suspension.
Next up for Jose Mourinho's side is a London derby against West Ham at the Tottenham Hotspur Stadium on Tuesday night - with full commentary of the 8:15pm kick-off LIVE ON talkSPORT!
Tottenham have extended the contracts of Jan Vertonghen and Michel Vorm until the end of the season, the Premier League club have confirmed.