Cadillac became the county seat after the so-called "Battle of Manton," in which a show of force was involved in enforcing a controversial decision to move the county seat from Manton, Michigan.
As of the census of 2000, there were 10,000 people, 4,118 households, and 2,577 families residing in the city. The population density was 1,466.0 per square mile (566.1/km²). There were 4,466 housing units at an average density of 654.7/sq mi (252.8/km²). The racial makeup of the city was 96.55% White, 0.21% Black or African American, 0.92% Native American, 0.63% Asian, 0.03% Pacific Islander, 0.28% from other races, and 1.38% from two or more races. 1.18% of the population were Hispanic or Latino of any race.
There were 4,118 households out of which 32.2% had children under the age of 18 living with them, 43.9% were married couples living together, 14.2% had a female householder with no husband present, and 37.4% were non-families. 31.8% of all households were made up of individuals and 14.4% had someone living alone who was 65 years of age or older. The average household size was 2.37 and the average family size was 2.96.
In the city the population was spread out with 26.2% under the age of 18, 9.6% from 18 to 24, 27.9% from 25 to 44, 19.6% from 45 to 64, and 16.7% who were 65 years of age or older. The median age was 36 years. For every 100 females there were 91.4 males. For every 100 females age 18 and over, there were 84.4 males.
The median income for a household in the city was $29,899, and the median income for a family was $36,825. Males had a median income of $29,773 versus $21,283 for females. The per capita income for the city was $16,801. About 10.9% of families and 13.7% of the population were below the poverty line, including 15.4% of those under age 18 and 13.3% of those age 65 or over.
Cadillac is situated as the confluence of three highways: US-131, M-55 and M-115. Prior to 2001, the northern terminus of the freeway portion of US-131 was located at the southern entrance to Cadillac. With the construction of a bypass, the US-131 freeway was extended around the east side of the city. The former route of the highway through downtown Cadillac was redesignated as Business US-131. In the city, BUS US-131 is named named Mitchell Street, after George Mitchell, but may be referred to as main street.
The city is serviced by rail via the Great Lakes Central Railroad. This is primarily a freight line, although passenger service is expected in the future.
Cadillac and Wexford County jointly operate a local public bus service. The Cadillac/Wexford Transit Authority is a demand-response system, and has been in operation since 1974. In recent years the Authority has been experimenting with a fixed-route service, operating a mid-day service in the summer. This proto-bus line runs between Cadillac West and the downtown.
The White Pine Trail's northern terminus is in Cadillac. The trail, which stretches 92 miles (148 km) and originates from Comstock Park, follows an abandoned railroad bed into the center of the city. The last mile of the trail is paved.