Pushmataha County is a county in the southeastern part of the U.S. state of Oklahoma. As of the 2020 census, the population was 10,812. Its county seat is Antlers.

The county was created at statehood from part of the former territory of the Choctaw Nation, which had its capital at the town of Tuskahoma. Planned by the Five Civilized Tribes as part of a state of Sequoyah, the new Oklahoma state also named the county for Pushmataha, an important Choctaw chief in the American Southeast. He had tried to ensure that his people would not have to cede their lands, but died in Washington, DC during a diplomatic trip in 1824. The Choctaw suffered Indian Removal to Indian Territory.

During prehistoric times, Pushmataha County was part of the territory during the Middle Woodland period of the Fourche Maline culture. Over time, and possibly through contact with the Middle Mississippian culture to their northeast, the Fourche Maline became the Caddoan Mississippian culture. Their center was at Spiro Mounds, near Spiro, Oklahoma. The elite organized the construction of complex earthwork mounds for burial and ritual ceremonial purposes, arranged around a large plaza that had been carefully graded. This center of political and religious leadership had a trade territory encompassing the full extent of the Kiamichi River and Little River valleys. This 80-acre site is preserved as Oklahoma's only Archeological State Park. The larger Mississippian culture traded from the Great Lakes to the Gulf Coast.

North America's history changed after the arrival of Europeans in 1492 under Christopher Columbus in the Caribbean. In the 16th century, European explorers began to enter the North American interior, seeking fame, treasures, and conquests on behalf of their empires.

France's Bernard de la Harpe explored the area of the modern Pushmataha County in 1719, in the era when France was establishing settlements on the Gulf Coast. They had founded New Orleans the year before. De la Harpe's exploration of the Mississippi River valley was part of an effort to seek trade with the native peoples and also a route to New Mexico. After this time France claimed this region of North America as La Louisiane. It explored Canada to the north from the Atlantic coast along the St. Lawrence River valley, where it founded New France.

The area that became Pushmataha County was bought by the United States from France as part of the large Louisiana Purchase in 1803.

The first American explorer to set foot in the modern county was Major Stephen H. Long in 1817. He was followed in 1819 by Thomas Nuttall, a scientist. Both explored the Kiamichi River valley, which Nuttall described in detail.

The Red River became an international boundary in 1819 when the United States concluded the Adams-Onis Treaty with the Spanish Empire. Fortifying the frontier from Spanish incursion, and securing it against potential uprisings by American Indians, was important to United States policy. The federal government established a chain of forts along its southern border.