In July 2017, Holmes signed his first professional deal with Reading,[4] making his debut for Reading on 6 March 2018 in a 1–1 draw against Bolton Wanderers.
Holmes had been in the academy at Reading since the age of 8, and a season ticket holder from age 11,[5]
On 26 February 2019, Holmes signed a new contract with Reading until the summer of 2022.[6]
On 5 December 2021, Holmes scored his first goal for Reading, a Bicycle kick against Hull City.[7]
On 17 June 2022, Holmes signed a new three-year contract with Reading.[8]
On 21 July 2022, Holmes was confirmed as Reading's Vice-Captain for the season, behind Captain Andy Yiadom.[9]
On 17 January 2024, Holmes signed for Premier League club Luton Town for an undisclosed fee, and returned to Reading on loan until the end of the season.[11][12]
Personal life
Born in England, Holmes is of Canadian descent through his grandmother and may be eligible to represent the Canada national team.[13]
Holmes is studying a degree on a part-time basis.[14]