Chairman Edin Rahic said an “unsatisifactory start to the season” by the Bantams had prompted the club’s decision to part company with the 32-year-old after just six games in charge.
The Bantams lie 17th in League One on six points with two wins to their name and their most recent encounter seeing them lose 2-1 at Fleetwood Town on Saturday.
His reign started with a 1-0 win at Shrewsbury but the Bantams lost four of their next five league games and were dumped out of the Carabao Cup by League Two Macclesfield on penalties.
“The decision is based on an unsatisfactory start to the season and performances not being good enough,” said Radic in a club statement on Monday night.
“We anticipated a much better start and the results have not matched expectations. We have acted swiftly to appoint a new head coach who we believe will take us towards achieving our goals this season and beyond.
“We care massively about this football club and believe this decision has been made at the right time, with everything very much to play for. We are now looking forward to naming our new head coach and moving forward, together, in a positive manner.”