Vaughan joined fellow Championship club Birmingham City on 26 November 2015, on loan until 2 January 2016. He made his debut as a second-half substitute in the next game, a 2–1 defeat at Brighton & Hove Albion, and made six appearances in total without scoring. The loan was then extended until the end of the season, when his contract with Huddersfield expired, at which point it would be converted to a one-year permanent contract with an option for a further season. He missed a penalty in Birmingham's FA Cup loss to Premier League club Bournemouth that would have given his side a lead, and finished the season with no goals from 16 appearances, most of which were as a substitute. During the close season, he was strongly linked with a move to Rangers, but no such move took place. He had been frustrated by his lack of first-team involvement in the second half of 2015–16 season, and when this continued into the new season – his only appearance was a start in the League Cup defeat to Oxford United – he chose to leave.