Defiance is governed by a city charter and a strong mayor/strong council. Council has seven members, one from each of four wards and three at-large councilmen. The city has a very responsive and qualified public service department including street maintenance, parks and recreation, building inspection, planning, zoning and engineering departments.

The police force is composed of 22 uniformed officers who are school-trained, two investigators and four dispatchers. The force operates 24 hours a day and utilizes four patrol vehicles. A 911 energency telephone system is in place.

The fire department consists of 15 full-time and 22 on-call members. Equipment includes four pumpers, one 90 foot aerial ladder truck, one heavy equipment truck, and two rescue vehicles. Rescue is provided by members of the department which have had a 110-hour training course. The fire protection class is 5.