Tom Carroll has opted to turn down a contract offered to him at the end of last season and will now join League Two side MK Dons as a free transfer.
Carroll joined City last July after a year out of the game and finishes his career with the Grecians on 45 appearances in all competitions and one goal.
Manager Gary Caldwell said: “Tom was excellent for the club last season after joining us following a year out of football. His experience was pivotal for the younger players in the group last season and we wish him all the very best at MK Dons.
"Everyone at the club wishes Tom the best and our thanks go to him for his efforts for the club during his time with us."