The City of Union is a 4th Class City with a City Administrator form of government.
The elected, policy-making body of the City consists of a Mayor and an eight-member Board of Aldermen. Union is divided into four wards and each ward has two aldermanic representatives. Municipal elections are held on the first Tuesday of April every year.
The City Administrator is appointed by the Board of Aldermen and is the full-time Administrative Officer of the City responsible for overseeing all daily operations and the municipal staff.