The 1909–10 Football League season was Birmingham Football Club's 18th in the Football League and their 10th in the Second Division. They finished bottom of the 20-team division, three points adrift of safety, so had to apply for re-election to the league for the 1910–11 season. They led the voting, ahead of Huddersfield Town who were elected to the league to replace Grimsby Town, who had finished the season in 19th place, above Birmingham. Alex Watson stepped down as secretary-manager at the end of the season, to be succeeded by Bob McRoberts, who had played as a forward for the club for seven years, and who became their first full-time manager, with no secretarial duties. They also took part in the 1909–10 FA Cup, entering at the first round proper and losing in that round to Leicester F