The Blues have lost just one of 11 games since Christmas and are unbeaten in 11 home matches. Leeds also enters in strong form with just two defeats in 14 games after knocking out Derby County 3-1 in the previous round.
Birmingham has won three of four home matches against Leeds, all in the Championship. The Whites have progressed from four of five FA Cup ties against Birmingham, with both teams seeking advancement to the fifth round.