January 1836 saw the establishment of the first post office. Flavius J. B. Crane was postmaster and the post office was in the Eagle Tavern. In March of this same year, there was a mail route started between Howell and the village of Kensington, and west to Grand Rapids. The City of Howell is the county seat of Livingston County. On 24 March 1836, the legislature passed an act organizing Livingston County and Howell was slated to become the county seat. This claim was vigorously opposed by a group from Brighton and was wholly relinquished by them until the county buildings were erected 12 years later. Howell at once assumed the dignity of the county seat. The town was originally called Livingston Center and incorporated on 14 March 1863.
As of the census of 2010, the city had 9,489 people, 4,028 households, and 2,237 families. The population density was. There were 4,551 housing units at an average density of. The city's racial makeup was 94.8% White, 0.4% African American, 0.7% Native American, 1.1% Asian, 0.3% Pacific Islander, 1.3% from other races, and 1.3% from two or more races. Hispanic or Latino people of any race were 3.5% of the population. There were 4,028 households, of which 30.4% had children under the age of 18 living with them, 36.8% were married couples living together, 13.6% had a female householder with no husband present, 5.1% had a male householder with no wife present, and 44.5% were non-families. 36.6% of all households were made up of individuals and 12% had someone living alone who was 65 years of age or older. The average household size was 2.25 and the average family size was 2.97. The median age in the city was 35.2 years. 23.2% of the city's population was under age 18; 10.1% was between the age 18 and 24; 29.8% was from age 25 to 44; 23.6% was from age 45 to 64; and 13.5% was age 65 or older. The city's gender makeup was 48.2% male and 51.8% female.
For many decades, Howell had the reputation of being associated with the Ku Klux Klan due to White Supremacist leader and Michigan Grand Dragon Robert E. Miles, who held KKK gatherings on his farm 12 miles north of the city with a Howell address. Miles died in 1992. However, these gatherings, including the burning of crosses, continued. The reputation persisted into the 2000s, with events such as a public auction of KKK items scheduled for Martin Luther King, Jr.'s birthday in 2005, the 2010 suspension of a teacher who removed students for wearing a Confederate flag and making anti-gay slurs, and students' racist tweets toward a racially mixed team in 2014. The Livingston Diversity Council, which was founded in response to a 1988 cross-burning on the lawn of a black family, promotes diversity and inclusion in the county. While they are numerous in Metro Detroit, Howell is not listed as being an active home to any hate group by the Southern Poverty Law Center.