Tishomingo is the largest city and the county seat of Johnston County, Oklahoma, United States. The population was 3,034 at the 2010 census, a decline of 4.1 percent from 3,162 at the 2000 census. It was the first capital of the Chickasaw Nation, from 1856 until Oklahoma statehood in 1907. The city is home to Murray State College, a community college with an annual enrollment of 3,015 students. Tishomingo is part of the Texoma region.
Tishomingo is located in south-central Johnston County at 34°14′8″N 96°40′39″W / 34.23556°N 96.67750°W / 34.23556; -96.67750 (34.235575, -96.677542). U.S. Route 377 runs through the center of the city, leading south 13 miles (21 km) to Madill and north 40 miles (64 km) to Ada. Oklahoma State Highway 22 also runs through the center of Tishomingo, leading southeast 23 miles (37 km) to Kenefic and west 4 miles (6 km) to Ravia. Ardmore is 31 miles (50 km) west of Tishomingo, and Oklahoma City is 116 miles (187 km) to the northwest.
According to the United States Census Bureau, Tishomingo has a total area of 4.5 square miles (11.6 km), of which 4.4 square miles (11.3 km) are land and 0.1 square miles (0.3 km), or 2.38%, are water. Pennington Creek flows through the west side of the city, leading south 2 miles (3 km) to the Washita River where it becomes an arm of Lake Texoma. The Tishomingo National Wildlife Refuge, covering the bottomlands of the river and creek valleys, borders the city to the south.
As of the census of 2000, there were 3,162 people, 1,218 households, and 768 families residing in the city. The population density was 671.0 people per square mile (259.2/km²). There were 1,407 housing units at an average density of 298.6 per square mile (115.3/km²). The racial makeup of the city was 73.12% White, 4.65% African American, 15.24% Native American, 0.44% Asian, 0.03% Pacific Islander, 0.98% from other races, and 5.53% from two or more races. Hispanic or Latino of any race were 3.04% of the population.
There were 1,218 households out of which 30.8% had children under the age of 18 living with them, 43.8% were married couples living together, 15.0% had a female householder with no husband present, and 36.9% were non-families. 32.3% of all households were made up of individuals and 16.3% 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 3.02.
In the city, the population was spread out with 24.8% under the age of 18, 14.2% from 18 to 24, 22.9% from 25 to 44, 19.8% from 45 to 64, and 18.3% who were 65 years of age or older. The median age was 36 years. For every 100 females, there were 88.4 males. For every 100 females age 18 and over, there were 85.8 males.
The median income for a household in the city was $20,938, and the median income for a family was $28,462. Males had a median income of $25,655 versus $16,957 for females. The per capita income for the city was $14,429. About 21.8% of families and 27.1% of the population were below the poverty line, including 31.6% of those under age 18 and 20.9% of those age 65 or over.