The 2005–06 season was Birmingham City Football Club's 103rd season in the English football league system and their fourth in the Premier League. Under the management of Steve Bruce, they finished in 18th position in the 20-team division, so were relegated to the Championship for 2006–07. They entered the 2005–06 FA Cup at the third round and progressed to the sixth round (quarter-final), in which they suffered their heaviest ever FA Cup defeat, and their heaviest defeat at St Andrew's in any competition, losing 7–0 at home to Liverpool. They also reached the quarter-final of the League Cup, in which they were eliminated by Manchester United.
Jiří Jarošík was top scorer in league competition, with just five goals. If all competitions are included, Jarošík and fellow loanee Mikael Forssell scored eight apiece.