From Ancoats in Manchester, Terry Flanagan had his first professional fight in 2009, beating Danny McDermid on points. After winning his first 12 fights between 2009 and 2012, he beat Dougie Curran in May 2012 to take the vacant English super featherweight title. He successfully defended the title four months later against Troy James.
Maintaining his 100% win record with wins over the likes of Gary Sykes, Derry Mathews, Michal Dufek, and Gyorgy Mizsei, Jr, he faced Martin Gethinin July 2014 for the vacant British lightweight title. Gethin retired at the end of the seventh round with an ear injury, giving Flanagan the title.
In February 2015 he beat Stephen Ormond after Ormond was disqualified in the tenth round for persistent use of his head, to take the WBOEuropean lightweight title, extending his 100% record to 27 wins and setting up a shot at the WBO World title. Flanagan seized the vacant title after a shoulder injury forced opponent Jose Zepeda to retire in the second round.