Coppell, who’s previously clubs included Reading and Crystal Palace, lasted just 112 days at City before announcing his retirement from football.
He said in a statement released through the League Managers’ Association: “It is with the deepest regret that I confirm my departure from Bristol City. I have made my decision after very careful consideration and I believe that it is in the best interests of both the club and me personally that we go our separate ways.
“Bristol City is an excellent club, with brilliant support and a chairman with great ambition for the club’s future. Whilst I was looking forward to the challenge of leading the players in this season’s campaign, unfortunately, it has become clear over recent weeks, that I found I could not, for whatever reason, become passionate about the role and give the commitment the position demands.
“I appreciate that the timing of my departure is not ideal, but I believe it is best for the club to appoint a new manager or indeed appoint Keith Millen, who has a deep knowledge of the club and the squad, at this stage of the season. That individual can then make decisions on signing players before the window closes and work with the squad for the full campaign.
“I am retiring from football management but still feel I have a contribution to make to the game sometime in the future. I would like to sincerely thank the chairman and the board for their understanding and I wish the club and its supporters every success.”