Oklahoma (IPAc-enen-us-Oklahoma.ogg?o?kl??ho?m?) is a state (U.S. state) located in the South Central region (South Central United States) of the United States of America. With an estimated 3,687,050 residents in 2009 and a land area of 68,667 square miles (177,847 km�), Oklahoma is the 28th most populous (List of U.S. states by population) and 20th-largest (List of U.S. states and territories by area) state. The states name is derived from the Choctaw words okla and humma, meaning "red people", and is known informally by its nickname, The Sooner (Sooners) State. Formed by the combination of Oklahoma Territory and Indian Territory on November 16, 1907, Oklahoma was the 46th state to enter the union. Its residents are known as Oklahomans, and its capital and largest city is Oklahoma City.

A major producer of natural gas (Natural Gas), oil (petroleum) and agriculture, Oklahoma relies on an economic base of aviation, energy, telecommunications, and biotechnology. It has one of the fastest growing economies in the nation, ranking among the top states in per capita income growth and gross domestic product growth. Oklahoma City and Tulsa serve as Oklahomas primary economic anchors, with nearly 60 percent of Oklahomans living in their metropolitan statistical areas. The state holds a mixed record in education and healthcare, and its largest universities participate in the NCAA and NAIA (National Association of Intercollegiate Athletics) athletic associations, with two collegiate athletic departments rated among the most successful in American history.

With small mountain ranges, prairie, and eastern forests, most of Oklahoma lies in the Great Plains and the U.S. Interior Highlands?a region especially prone to severe weather. In addition to having a prevalence of German (Germans), Irish (Irish people), British (British people) and Native American (Native Americans in the United States) ancestry, more than 25 Native American languages are spoken in Oklahoma, the most of any state. It is located on a confluence of three major American cultural regions and historically served as a route for cattle drives, a destination for southern settlers, and a government-sanctioned territory (Territories of the United States) for Native Americans. Part of the Bible Belt, widespread belief in evangelical (Evangelicalism) Christianity makes it one of the most politically conservative (Conservatism in the United States) states, though Oklahoma has more voters registered with the Democratic Party (Democratic Party (United States)) than with any other party.