The Clay County Courthouse on Louisville's public square
|Area||0.75 sq mi (2 km2)|
|- land||0.75 sq mi (2 km2)|
|- water||0.00 sq mi (0 km2)|
|Density||1,794.1 / sq mi (693 / km2)|
|- summer (DST)||CDT (UTC-5)|
|Wikimedia Commons: Louisville, Illinois|
|Although spelled the same as Louisville, Kentucky, the general pronunciation of the town is "Lewis-ville".|
Louisville is located at (38.771356, -88.506301).
According to the 2010 census, the village has a total area of 0.75 square miles (1.9 km2), all land.
As of the census of 2000, there were 1,242 people, 503 households, and 311 families residing in the village. The population density was 1,794.1 people per square mile (695.0/km²). There were 543 housing units at an average density of 784.4 per square mile (303.8/km²). The racial makeup of the village was 99.28% White, 0.16% African American, 0.16% Native American, 0.08% Asian, 0.24% from other races, and 0.08% from two or more races. Hispanic or Latino of any race were 0.40% of the population.
There were 503 households out of which 28.4% had children under the age of 18 living with them, 48.7% were married couples living together, 9.7% had a female householder with no husband present, and 38.0% were non-families. 34.4% of all households were made up of individuals and 20.1% had someone living alone who was 65 years of age or older. The average household size was 2.31 and the average family size was 2.97.
In the village the population was spread out with 23.7% under the age of 18, 8.5% from 18 to 24, 24.5% from 25 to 44, 21.9% from 45 to 64, and 21.4% who were 65 years of age or older. The median age was 39 years. For every 100 females there were 92.3 males. For every 100 females age 18 and over, there were 84.8 males.
The median income for a household in the village was $25,250, and the median income for a family was $35,673. Males had a median income of $27,083 versus $21,719 for females. The per capita income for the village was $13,119. About 13.1% of families and 18.9% of the population were below the poverty line, including 19.7% of those under age 18 and 15.6% of those age 65 or over.
 Notable people
- Tom Richardson, pinch hitter for the St. Louis Browns; born in Louisville
- John Riley Tanner Governor of Illinois January 11, 1897 – January 14, 1901; home and farm in Louisville, IL
- "Find a County". National Association of Counties. Retrieved 2011-06-07.
- "US Gazetteer files: 2010, 2000, and 1990". United States Census Bureau. 2011-02-12. Retrieved 2011-04-23.
- "2010 Census U.S. Gazetteer Files for Places – Illinois". United States Census. Retrieved 2012-10-13.
- "American FactFinder". United States Census Bureau. Retrieved 2008-01-31.