Holt County is a county located in the northwestern portion of the U.S. state of Missouri. As of the 2010 census, the population was 4,912. Its county seat is Oregon. The county was organized February 15, 1841. Originally named Nodaway County, it was soon renamed for David Rice Holt (1803–1840), a Missouri state legislator from Platte County.
According to the U.S. Census Bureau, the county has a total area of 470 square miles (1,200 km), of which 463 square miles (1,200 km) is land and 7.7 square miles (20 km) (1.6%) is water.
As of the census of 2000, there were 5,351 people, 2,237 households, and 1,503 families residing in the county. The population density was 12 people per square mile (4/km²). There were 2,931 housing units at an average density of 6 per square mile (2/km²). The racial makeup of the county was 98.47% White, 0.11% Black or African American, 0.47% Native American, 0.07% Asian, 0.02% Pacific Islander, 0.11% from other races, and 0.75% from two or more races. Approximately 0.39% of the population were Hispanic or Latino of any race.
There were 2,237 households out of which 28.20% had children under the age of 18 living with them, 57.30% were married couples living together, 6.10% had a female householder with no husband present, and 32.80% were non-families. 29.70% of all households were made up of individuals and 16.70% had someone living alone who was 65 years of age or older. The average household size was 2.35 and the average family size was 2.91.
In the county, the population was spread out with 23.80% under the age of 18, 6.50% from 18 to 24, 24.40% from 25 to 44, 23.90% from 45 to 64, and 21.50% who were 65 years of age or older. The median age was 42 years. For every 100 females there were 97.70 males. For every 100 females age 18 and over, there were 92.80 males.
The median income for a household in the county was $29,461, and the median income for a family was $35,685. Males had a median income of $26,966 versus $17,846 for females. The per capita income for the county was $15,876. About 10.50% of families and 13.00% of the population were below the poverty line, including 15.90% of those under age 18 and 11.90% of those age 65 or over.