The 60-year-old leaves having guided the U's back into the Football League in 2014 but with the club currently in 18th place in League Two.
Their last victory was the 2-1 success against Northampton Town in mid-October.
Money's exit leaves two clubs in the division currently searching for new managers after York City parted company with Russ Wilcox recently.
Former Dundee United boss Jackie McNamara has been linked with the Bootham Crescent role.