The National League South strugglers parted company with Chris Todd last week.
Winless since September, the Tigers have slipped to second bottom after a terrible run.
They believe Cook, the UEFA Pro Coaching License holder, can steer them to safety.
The former Coventry City player says he can’t wait to get started and wants to get the fans on board quickly.
Director Alex Petheram said: “We’re delighted to announce that Mike Cook is the new manager at Gloucester City AFC.
“Mike brings with him a wealth of football knowledge, experience and most of all he knows what Gloucester City is all about.
“He understands the club, the area and we believe he has what it takes to get us out of the position we currently find ourselves in.”