The city sits atop one of the nation's largest oil fields, with wells even on the lawn of the Capitol. First discovered in 1928, the field was rapidly developed throughout the city. It still produces large quantities of high-gravity oil. Oil well equipment manufacture became one of the city's major industries.

Oklahoma City's stockyards and meat packing plants are the largest in the state. The city is also a grain milling and cotton processing center. Iron and steel, furniture, tire manufacturing, electrical equipment, electronics, and aircraft and automobile assembly are other industries. Tinker Air Force Base is southeast of the city.