The England international right-back, who joined Spurs from Sheffield United in 2009, signed a new contract on Monday that will keep at White Hart Lane until 2019.
"It's fantastic," he told the club's official website. "When I first signed here at the age of 18, I always wanted to make it a long stay. The lads are fantastic as well as the manager and everyone surrounding the club – it just makes it a lot easier when they do offer you a contract to sign it.
"I'm very thankful to the chairman for giving me an extension on the contract and hopefully I can repay him by putting the performances in on the pitch and getting that top-four spot.
"Tottenham have always had great players and it has gone very well for us since the start of the season. The players we've got and the depth around the team is very good, so it's bright things (ahead) for Tottenham and hopefully everything comes together."
Walker, 23, has played every minute of Tottenham's 2013-14 Premier League campaign to date.