His performances earned him a move to Premier League club Tottenham Hotspur, before being immediately loaned back to Sheffield United.

After further loan spells at Queens Park Rangers and Aston Villa, Walker cemented his place in Tottenham's first team.

[14] Soon after returning to United, Walker made his first-team debut for the club on 13 January 2009, starting in a third round FA Cup tie against Leyton Orient.

[19] On 22 July 2009, Walker signed for Premier League club Tottenham Hotspur, along with Sheffield United teammate Kyle Naughton, for a combined fee of £9 million.

[20] While at Sheffield United, he was virtually ever-present at right-back for the first half of the season, but was unexpectedly recalled by Tottenham on 1 February 2010, just before the close of the January 2010 transfer window, after Alan Hutton was loaned out to Sunderland.

[22] At the start of the following season, Walker went out on loan once more signing an initial one-month deal with Queens Park Rangers due to injuries at the club in the right-back position.

[24] After leaving QPR, Walker joined Premier League club Aston Villa on loan until the end of the 2010–11 season.

[28] On leaving Villa Park, Walker suggested that he would be happy to return to the club the next season,[29] for his first-team opportunities at Tottenham were limited.

[39] Walker was part of the Tottenham team that lost 2–0 to Chelsea on 1 March at Wembley Stadium in the 2015 League Cup final.

[46] On 25 February, Walker started in the 2018 EFL Cup final against Arsenal, and played the whole 90 minutes, with Manchester City winning 3–0 to obtain their first piece of silverware of the 2017–18 season, and their first trophy overall under Pep Guardiola.

[48] Walker started in the 2019 FA Cup final against Watford on 18 May as City won the first domestic treble in English men's football.

[59] City won the 2021–22 Premier League on 22 May 2022 as teammate İlkay Gündoğan scored two goals in a 3–2 home victory against Aston Villa to overturn a two-goal deficit.

[63] In April 2023, Pep Guardiola shifted the tactics of City in the middle of the 2022–23 season, resulting in a decrease of starts and game time for Walker.

Questioned on this in a press conference, Guardiola stated that Walker did not in his opinion have "every one of the characteristics" required for a new role in a 3–2–4–1 formation, but also mentioned that he had not "lost faith" in him.

[64][65][66] During the 2022–23 Champions League season, Walker displayed incredible performances over two legs against Real Madrid in the semi-finals, being praised by analysts especially for nullifying the threat of Vinícius Júnior.

[73] On 3 June, Walker won the FA Cup, beating Manchester United in the final, in which he started and played for 95 minutes.

On 6 August, with De Bruyne benched, Walker captained the team in the 2023 FA Community Shield, which they lost on penalties to Arsenal.

[91] On 24 January 2025, Walker joined Serie A club AC Milan on loan until the end of the 2024–25 season, with an option for a permanent transfer.

[92] Walker made his debut for the England national under-19 team on 10 February 2009, coming on as a 78th-minute substitute in a 3–0 home loss to Spain in a friendly.

[94] Walker's debut for the England national under-21 team came on 3 March 2010 when starting a 2–1 home defeat to Greece in a 2011 UEFA European Under-21 Championship qualification group match.

[95] Following his first run of regular Premier League starts, Walker was called up to the senior national team in February and March 2011.

[102] Walker was deployed as a centre-back in a back three by England's manager Gareth Southgate[103] as the team reached the semi-final for the first time since 1990.

[104] On 5 September 2020, he was sent off in a 1–0 away win over Iceland in the 2020–21 Nations League, becoming the first Englishman to get an international red card since Raheem Sterling in June 2014.

[115] In the round of 16 match against Slovakia, Walker's long throw-in was flicked on by Marc Guéhi for Jude Bellingham's equalising goal in the 95th minute.

[116] Kyle Walker is renowned for his speed and strength,[117][118][119] and has been identified by players such as Neymar and Eden Hazard as one of the toughest opponents they have ever faced.

[128][129] In addition to his defensive qualities, Walker is also a good attacking full-back who is capable of making overlapping runs and delivering crosses into the box.

[133][134] After the news of his affair with Goodman broke, Walker publicly apologised to Kilner, stating that he had made "idiot choices" and needed to "own up to my mistakes".

[136] On 5 April 2020, Manchester City began a disciplinary procedure against Walker after it was reported that he had broken national lockdown rules and invited two prostitutes to his home amid the COVID-19 pandemic.