Walker joined Spurs from Sheffield United in 2008 and has gone on to make 112 first team appearances and cement a regular berth in the England team.
And the 23-year-old, named PFA Young Player of the Year in 2012, believes he can help deliver major honours to White Hart Lane.
“It’s fantastic,” said Walker. “I’ve been here five years and hopefully there’s a lot of medals to come.
“I’m very thankful to the chairman for offering me the contract and hopefully I can repay him with performances on the pitch and getting that top four spot that we need.”
Walker has been an ever-present in the Premier League this season, helping Spurs to six clean sheets in nine games, including Sunday’s 1-0 victory over Hull.
Striker Roberto Soldado scored the decisive goal to shoot his team up to fourth in the Premier League table and believes Spurs are heading in the right direction.
“Apart from the blip against West Ham I think we’ve done very well at the back recently to not have any goals scored against us,” said Soldado. “We’re moving forward.”