In an interview with Sky Sports in June 2020, Blackburn midfielder Bradley Dack reported "Playing Sunday League after I was released by Charlton helped me but, at the time, it was the last thing I wanted to do. I wanted to stay at an academy but I wasn't deemed good enough to be at an academy. It was tough to take. I went on trial to Fulham and Norwich and they said I wasn't better than players they already had."
After for playing for youth football team Corinthian in the Kent Youth League, Dack then had a trial for Gillingham in 2007 and signed for them at Under-16 level. He signed his first professional contract in May 2012.
Scoring proficiently during the 2012 pre season, he made his professional debut on 14th August 2012 against Bristol City in the Football League Cup. In January 2013 he had a month's loan at Braintree. He ended the 2012/13 season as Gillingham's young player of the season as they won the League Two title. He went on to make 185 appearances for Gillingham, scoring 38 goals and was the League One Player of the Year in 2014/15.
On 27th June 2017 he signed for League One Blackburn for £750,000. They finished second in League One in 2017/18.