Scanlon joined Liverpool from Birmingham City as a 15-year-old, in a reported £500,000 deal in December 2020.
[6] Scanlon continued to train with the Liverpool first-team squad during the 2023–24 season following an injury to first-choice left-back Andrew Robertson,[7] and was named among the match day substitutes for the Premier League match against local rivals Everton on 21 October 2023.
[8] He made his senior debut for Liverpool in a 5–1 UEFA Europa League victory over Toulouse at Anfield on 26 October 2023.
[10] On 29 August 2024, Scanlon joined Championship side Millwall on loan until the end of the season.
[11] On 21 January 2025, Scanlon scored his first professional goal in a 2-2 draw against Cardiff City.