[4] He began his career as a "quick" winger or forward, before a growth spurt at age 11 led to him moving to centre back.

[3][4] On 23 July 2021, Peart-Harris transferred to Premier League club Brentford and signed a four-year contract, with the option of a further year, for an undisclosed fee,[7] reported to be £1.4 million.

[3] Well down the midfield pecking order following the 2022–23 pre-season, Peart-Harris joined League One club Forest Green Rovers on loan until January 2023.

[13][14] During the 2023–24 pre-season, Peart-Harris was named in Brentford's 2023 Premier League Summer Series squad and made two appearances at the tournament.

[9] He made five substitute appearances prior to his departure on loan to League One club Portsmouth for the remainder of the 2023–24 season on 22 January 2024.

[3][26][27][28][29][30][31] He made just one EFL Cup substitute appearance early in the regular season,[32] prior to joining Championship club Swansea City on a season-long loan.

[7] He was an unused substitute during England's three 2019 European U17 Championship elite round qualifying matches in March 2019,[9] but was not named in the squad for the tournament finals.