On 23 July 2014, Davies joined Tottenham Hotspur on a five-year contract for an undisclosed fee. He joined on the same day as his Swansea teammate Michel Vorm, with Gylfi Sigurðsson being exchanged as part of the deal. Davies made his Premier League debut for Tottenham Hotspur as a late substitute in a 0–3 defeat to Liverpool. He made his first start for the club in the league in a 2–1 away win at Hull City on 23 November 2014. He was an unused substitute for the 2015 League Cup Final at Wembley Stadium on 1 March 2015, in which Tottenham were beaten 2–0 by Chelsea.
He scored his first goal for the club on 8 January 2017, scoring a header in an FA Cup tie against Aston Villa. Davies signed a new four-year contract at Tottenham on 9 March 2017, extending his deal to 2021.
Davies scored his second Tottenham goal and his first for them in the Premier League against Hull City on the final day of the 2016–17 season. A first time strike from outside the box into the top left corner added a 6th goal in an eventual 7–1 win for Tottenham.
Davies started for Tottenham in the opening match of the 2017–18 season, and scored a goal in a 2–0 win away to Newcastle United.