Logan County is a county located in the state of Ohio, United States. As of 2000, the population was 46,005. The county seat is Bellefontaine.

Adjacent counties
Two U.S. Routes pass through Logan County: U.S. Route 33, which runs from northwest to southeast through the middle of the county, and U.S. Route 68, which runs north-south through the middle of the county. While US 68 is two lanes throughout Logan County, US 33 is two lanes only between the Auglaize County line and Huntsville; from Huntsville to the Union County line, it is a four-lane freeway.
Among state routes, the chief highway is State Route 47, a two-lane highway that runs east-west through the middle of the county. Other state highways in Logan County include State Routes 117, 235, 245, 273, 274, 287, 292, 347, 365, 366, 368, 508, 533, 540, 559, 706, 708, and 720.

Major highways
2000 46,005 1990 42,310 1980 39,155 1970 35,072 1960 34,803 1950 31,329 1940 29,624 1930 28,981 1920 30,104 1910 30,084 1900 30,420 1890 27,386 1880 26,267 1870 23,028 1860 20,996 1850 19,162 1840 14,015 1830 6,440 1820 3,159 As of the census of 2000, there were 46,005 people, 17,956 households, and 12,730 families residing in the county. The population density was 100 people per square mile (39/km²). There were 21,571 housing units at an average density of 47 per square mile (18/km²). The racial makeup of the county was 96.15% White, 1.71% Black or African American, 0.20% Native American, 0.40% Asian, 0.03% Pacific Islander, 0.27% from other races, and 1.24% from two or more races. 0.72% of the population were Hispanic or Latino of any race. 96.8% spoke English, 1.0% German and 1.0% Spanish as their first language.
There were 17,956 households out of which 33.30% had children under the age of 18 living with them, 57.00% were married couples living together, 9.50% had a female householder with no husband present, and 29.10% were non-families. 24.80% of all households were made up of individuals and 10.30% had someone living alone who was 65 years of age or older. The average household size was 2.53 and the average family size was 3.01.
In the county, the population was spread out with 26.70% under the age of 18, 8.20% from 18 to 24, 27.90% from 25 to 44, 23.30% from 45 to 64, and 13.90% who were 65 years of age or older. The median age was 37 years. For every 100 females there were 96.10 males. For every 100 females age 18 and over, there were 93.60 males.
The median income for a household in the county was $41,479, and the median income for a family was $47,516. Males had a median income of $37,134 versus $24,739 for females. The per capita income for the county was $18,984. About 7.10% of families and 9.30% of the population were below the poverty line, including 11.80% of those under age 18 and 8.50% of those age 65 or over.

Demographics
Main article: Ohio county government.

Government

Localities
There are twelve incorporated municipalities in Logan County:

Municipalities

Bellefontaine Cities

Belle Center
De Graff
Huntsville
Lakeview
Quincy
Rushsylvania
Russells Point
Valley Hi
West Liberty
West Mansfield
Zanesfield Townships
There are also a number of unincorporated places in Logan County:

Big Springs
East Liberty
Horton
Lewistown
Logansville
Middleburg
New Jerusalem
North Greenfield
Northwood
Pickrelltown
Walnut Grove