As of the census of 2000, there were 40,867 people, 16,718 households, and 11,318 families residing in the county. The population density was 59 people per square mile. There were 18,707 housing units at an average density of 27 per square mile. The racial makeup of the county was 92.16% White, 5.22% Black or African American, 0.56% Native American, 0.44% Asian, 0.01% Pacific Islander, 0.26% from other races, and 1.36% from two or more races. Approximately 1.01% of the population were Hispanic or Latino of any race. Among the major first ancestries reported in Butler County were 31.7% American, 13.8% German, 11.6% Irish and 10.5% English. There were 16,718 households out of which 29.70% had children under the age of 18 living with them, 52.50% were married couples living together, 11.60% had a female householder with no husband present, and 32.30% were non-families. 28.00% of all households were made up of individuals and 12.70% had someone living alone who was 65 years of age or older. The average household size was 2.39 and the average family size was 2.91. In the county, the population was spread out with 24.20% under the age of 18, 8.40% from 18 to 24, 26.60% from 25 to 44, 24.10% from 45 to 64, and 16.70% who were 65 years of age or older. The median age was 39 years. For every 100 females there were 92.00 males. For every 100 females age 18 and over, there were 87.10 males. The median income for a household in the county was $34,422, and the median income for a family was $42,713. Males had a median income of $27,449 versus $19,374 for females. The per capita income for the county was $20,282. About 14.00% of families and 18.60% of the population were below the poverty line, including 25.90% of those under age 18 and 16.90% of those age 65 or over.
Religion
According to the Association of Religion Data Archives County Membership Report, most residents in Butler County do not adhere to a religion. Among those who do adhere to a religion, the majority of Butler County residents' religious affiliations are:
The main religious families among all adherents in Butler County are:
45.27% Baptists
14.64% Nondenominationals
11.92% Catholics
9.30% Pentecostals
6.67% Methodists
Education
Of adults 25 years of age and older in Butler County, 70.5% possesses a high school diploma or higher while 11.6% holds a bachelor's degree or higher as their highest educational attainment.
Three Rivers College - Poplar Bluff - A public, two-year community college.
Public libraries
Fisk Community Library
Poplar Bluff Public Library
Politics
Local
The Republican Party completely controls all politics at the local level in Butler County.
State
Butler County is divided into two legislative districts in the Missouri House of Representatives:
District 152 is currently represented by . It consists of all of the cities of Neelyville, Qulin, and Poplar Bluff; all of the census-designated place of Harviell; and the unincorporated communities of Angus, Batesville, Belcher, Booser, Broseley, Fagus, Hubbel, Kremlin, Loma Linda, Nyssa, Oglesville, Platanus, Resnik, Roxie, Taft, and Vastus.
District 153 is currently represented by . It consists of all of the city of Fisk and the unincorporated communities of Ash Hill, Barron, Empire, Halloran, Hamtown, Hendrickson, Hilliard, Keener, Kinzer, Morocco, Rombauer, and Wilby.
All of Butler County is included in Missouri's 25th Senatorial District and is represented by Republican in the Missouri Senate.
Voters in Butler County from both political parties supported candidates who finished in second place in the state at large and nationally.
Hillary Rodham Clinton received more votes, a total of 2,490, than any candidate from either party in Butler County during the 2008 Missouri presidential preference primary.
