Mill Creek is a non-charter code city with a council–manager government. The city council is composed of seven members elected in non-partisan, at-large elections to four-year terms. The councilmembers elect a ceremonial mayor and mayor pro tem from its members and appoint a city manager to execute its legislative policies. The current mayor is councilman Brian Holtzclaw, who was appointed in 2020 after the mid-term resignation of Pam Pruitt. The city manager is Michael Ciaravino, who was appointed in May 2019 after the position was held by an interim manager for a year.