In early February 2002, Devlin signed for Birmingham City on a month's loan, while Paul Furlong made a similar move in the other direction. Devlin's loan was extended to three months, during which he made 11 appearances, scored once, an equaliser as Birmingham came back from two goals down to draw with top-of-the-table Wolverhampton Wanderers, and helped the team finish in the play-off positions; he signed a three-year permanent contract in May. Devlin converted his kick in the penalty shoot-out in the play-off final against Norwich City by which Birmingham gained promotion to the Premier League.