Former City youth coach Eyre has signed a three-year deal with Rochdale.
"I am looking forward to the challenge," said Eyre who spent 21-years at City.
"Of course it is an emotional wrench leaving the Blues especially when the club has just had such hugely successful season and looks poised to go on to even better things but this is an opportunity I couldn't turn down.
"Rochdale is a well-run club with a loyal band of supporters and one which has ambition to move a step higher. It mirrors my own ambition. There are some good players at the club and hopefully with my contacts in the game I can bring a few more in."