Derbyshire returned to England when he signed for Birmingham City on 16 August 2010 on loan for the 2010–11 Premier League season, with a possibility of the deal being made permanent at the end of that time. He made his debut against former club Blackburn Rovers on 21 August as a second-half substitute for fellow new signing Nikola Žigić, and scored his first goal for the club five days later in a 3–2 League Cup victory over Rochdale. After waiting until January 2011 for his first Premier League start for Birmingham, against Blackpool, he then scored twice in the 4–1 win at Millwall in the third round of the FA Cup. Derbyshire never established himself in the first team, and despite making five appearances in that season's League Cup competition, he was omitted from Birmingham's squad for the final, in which Birmingham achieved a shock 2–1 victory against Arsenal. He left the club at the end of the season after their relegation from the Premier League.