Leeds United After winning his division with under-eights' junior side Heworth, Clarke joined
Leeds United's academy in 2009. He graduated through their academy and, together with
Niall Huggins, signed a two-year scholarship with Leeds United in May 2017. On 24 November 2017, Clarke signed a professional contract at Leeds United. For the
2018–19 season Clarke was given the number 47 shirt and made his professional debut on 6 October 2018, coming on as a late substitute in Leeds' 1–1 draw against
Brentford at
Elland Road. He scored his first goal for the club in the 56th minute of a league tie against
Aston Villa at
Villa Park on 23 December 2018, having come on as a half-time substitute. Clarke made his first career start in the
FA Cup third-round game against
Queens Park Rangers, playing all 90 minutes in a 2–1 defeat. He made his first league start for Leeds in a 2–0 win against
Derby County on 11 January 2019, winning the man of the match award after assisting both goals. During the second half of Leeds' 1–1 league tie at
Middlesbrough on 9 February 2019, Clarke, who had been substituted at half-time, was stretchered off the substitutes bench in the second half and taken to hospital after collapsing. Clarke was kept under supervision at James Cook University Hospital until the following day. After a spell out recovering with a virus believed to be behind the health scare,
Marcelo Bielsa said that Clarke would return to training on 4 March. He returned to the first team on 16 March as a 77th-minute replacement for
Luke Ayling and went on to make seven further appearances that season, albeit none of them as part of the starting lineup. He was one of three players nominated for the club's end of season awards for Young Player Of The Season alongside
Tyler Roberts and
Jamie Shackleton, with Clarke winning the award on 28 April 2019, at the club's annual ceremony. During the
2018–19 season, Clarke played 25 games in all competitions, scoring two goals, after Leeds finished the regular season in third place having dropped out of the automatic promotion places with three games left following a defeat to 10-man
Wigan on 19 April. Leeds qualified for the playoffs versus sixth-placed
Derby County, with Clarke coming on as a second-half substitute in the first leg of the playoffs (a 1–0 away win at Pride Park), and playing as a second-half substitute in the return leg as Leeds lost 2–4 in an encounter that saw Derby progress 4–3 on aggregate to the final against
Aston Villa.
Tottenham Hotspur On 2 July 2019, Clarke signed for
Premier League side
Tottenham Hotspur for an undisclosed fee until 2023. The fee was believed to be in the region of £10 million, with further add ons. As part of the deal taking him to Tottenham, on the same day, Clarke re-joined Leeds on loan for the entirety of the 2019–20 season. He made his second debut for the club on 13 August in the
EFL Cup against
Salford City, and featured in the second round against
Stoke City. Clarke eventually made his first league appearance of the season on 23 November at
Kenilworth Road, when he came on as a 71st-minute substitute in Leeds' 2–1 win against
Luton Town for
Tyler Roberts. On 27 December, Clarke's loan to Leeds was terminated early after he was recalled by parent club Tottenham by new manager
José Mourinho, due to a lack of playing time at Elland Road, having made only three appearances during his brief return to the Whites. Leeds' manager Marcelo Bielsa commented, "I am very grateful with Clarke. He made his contribution in this part of the season, even if I didn't use him. In the last days, he improved his performance, but just when this process was going on Tottenham decided to ask Leeds for Clarke to come back." He signed for
Queens Park Rangers on a six-month loan deal on 16 January 2020 and made his debut for QPR two days later, coming on as a substitute against his former club Leeds in a match that ended in a 1–0 win for the Londoners. Clarke made his debut for Tottenham on 22 October 2020, coming off the bench as an 86th-minute substitute for
Carlos Vinícius in the
Europa League against
LASK. On 14 January 2021, Clarke joined
Stoke City on loan until the end of the
2020–21 season. Clarke played 14 times for Stoke before he suffered a season-ending achilles injury at the start of April. He joined
Sunderland on loan until the end of the 2021–22 season on 26 January 2022.
Sunderland On 9 July 2022, he joined Sunderland on a permanent transfer for an undisclosed fee on a four-year deal. Clarke's first game was the opening Championship league game against Coventry City which finished 1–1 with Clarke scoring Sunderland's only goal in the game.
Ipswich Town On 24 August 2024, newly promoted
Premier League club
Ipswich Town confirmed they had signed Clarke from Sunderland for an undisclosed fee. The BBC reported that the fee was £15 million with an additional £5 million add-ons. Clarke scored his first goal for Ipswich in a 3–0 victory against
Bristol Rovers in the third round of the
FA Cup on 12 January 2025. ==International career==