Walker joined Spurs in 2009 and has since made 155 Premier League appearances for the north London side
His new deal will run until 2021.
The 26-year-old becomes the seventh Tottenham player to extend his commitment this month, following Christian Eriksen, Harry Winks, Tom Carroll, Eric Dier, Danny Rose and Dele Alli.
"It's a great honour," Walker told Spurs TV
"I want to say a big thank you to the chairman and the manager for putting their faith in me.
"It's been a long stay here but a very enjoyable one
I'm fully enjoying it
It's like my second home now and I'm happy to commit my future to Tottenham Hotspur."
Walker has established himself as one of Tottenham's most consistent performers under Mauricio Pochettino and was an integral part of the team qualifying for the Champions League last season.
He has made a strong start to the current campaign, registering two assists in Spurs' opening five league games and helping Pochettino's men record three clean sheets.
Walker's performances have also earned him a regular spot for England, for whom he has 20 caps so far, and he started Sam Allardyce's first game in charge against Slovakia three weeks ago.
Spurs have announced a spate of new contracts this month and are expected to confirm more in the coming weeks, with Jan Vertonghen and Erik Lamela both in talks over new deals.
Source : PA
Source: PA