The Wales fullback told the Spurs website: "I'm happy to be putting pen to paper and hopefully I can just kick on and do well now.
"I thought I was progressing really well at the start of last season and I learnt a lot off the pitch during my time on the sidelines which I can add to my game.
"It's a great feeling to be part of the long-term plans here. It's a great club with fantastic coaching staff, and I think everyone here wants to be part of it.
"I'm committed to the Club now and I am looking to achieve many things here and do my best for Spurs."