Coming through the youth system of Charlton Athletic, Asiimwe made his professional debut for the club as a 17–year–old, playing the full game in a 3–2 EFL Trophy second round defeat away at Plymouth Argyle on 22 November 2022.[3][4][5]
On 7 May 2023, Asiimwe made his League One debut for Charlton Athletic, coming on in the 74th minute of the club's final game of the 2022–23 season during a 2–2 draw away at Cheltenham Town.[6]
On 22 May 2023, Asiimwe signed his first professional contract with the club.[7][8]
Ahead of the 2023–24 season, Asiimwe was integrated into Charlton Athletic's first-team squad. On 8 July 2023 – in the club's second pre-season match against Dartford at Princes Park – Asiimwe scored both goals in a 2–1 victory.[9][10] On 19 July 2023, Asiimwe played his first game at The Valley in the club's final pre-season game of the 2023–24 season in a 3–2 defeat to Aberdeen. Asiimwe scored an own goal in the match after three minutes.[11]
On 5 August 2023, Asiimwe played his first full League One game in the club's first match of the 2023–24 season, completing the full 90 minutes in a 1–0 victory over Leyton Orient.[12]
Hartlepool United (loan)
On 19 September 2024, Asiimwe joined Hartlepool United on a short-term loan.[13] On 21 September, Asiimwe started his first match for Hartlepool United, playing the first 60 minutes of a 1–0 home defeat to Dagenham & Redbridge.[14] On 29 October, it was announced that Asiimwe would return to Charlton at the end of his short-term loan having made five appearances in total for Hartlepool.[15]
