Louisiana is a city in Pike County, Missouri, United States. The population was 3,863 at the 2000 census. Louisiana is located in northeast Missouri, on the Mississippi River south of Hannibal.
Louisiana is located at 39°26′45″N 91°3′24″W / 39.44583°N 91.05667°W / 39.44583; -91.05667 (39.445833, -91.056584). According to the United States Census Bureau, the city has a total area of 3.4 square miles (8.9 km²), of which 3.1 square miles (8.1 km²) is land and 0.3 square mile (0.8 km²) (8.48%) is water.
As of the census of 2000, there were 3,863 people, 1,590 households, and 1,006 families residing in the city. The population density was 1,234.4 people per square mile (476.5/km²). There were 1,843 housing units at an average density of 588.9 per square mile (227.3/km²). The racial makeup of the city was 90.27% White, 5.72% African American, 0.36% Native American, 0.26% Asian, 0.13% Pacific Islander, 2.20% from other races, and 1.06% from two or more races. Hispanic or Latino of any race were 3.93% of the population.