Great Plains Airlines was a regional airline headquartered in Tulsa, Oklahoma.

Ozark Air Lines was a local service carrier in the United States that operated from 1950 until 1986, when it was purchased by Trans World Airlines (TWA). In 2001, TWA was merged into American Airlines. A smaller regional airline that used the Ozark name operated in 2000–2001. From 1950 until 1986, Ozark's headquarters was located at St. Louis Lambert International Airport.