In preseason, Millwall announced the death of owner and chairman John Berylson, who passed away in an accident on 4 July.

On 18th October 2023, the club announced it had mutually agreed to part company with first team manager Gary Rowett.

Neil Harris returned to manage the club, winning eight of their final 13 games, including five in a row to finish the season strongly in 13th place.

† Signed for the Under-21s On 19 June, Millwall announced their pre-season schedule, with matches against Gillingham, Sutton United, Charlton Athletic and Fortuna Sittard.

[43] Win Draw Loss Fixtures As a Championship club, Millwall entered the FA Cup in the third round and were drawn at home to Leicester City.