On 28 January 2011, Davies signed for rivals Birmingham City on a three-and-a-half-year contract for an undisclosed fee. He was given the squad number 32. Davies was cup-tied for Birmingham's victory in the 2011 League Cup Final. He made his first-team debut in a 3–1 home defeat to former club West Bromwich Albion in March, coming into the starting eleven in place of the injured Martin Jiránek. His first goal for the club came when he opened the scoring with a header from a Jordon Mutch corner on 6 August 2011 as Birmingham went on to lose 2–1 at Derby County. In Birmingham's first match in major European competition for nearly 50 years, the Europa League play-off round first leg against Portuguese club Nacional, which finished goalless, Davies made a well-timed tackle from behind to prevent Mateus opening the scoring.