The McDonnell Aircraft Corporation was an American aerospace manufacturer, based near St. Louis, Missouri. It was founded in 1938 by James Smith McDonnell , and merged, with the Douglas Aircraft Company, into McDonnell Douglas in 1967.

The advent of World War II was a major boost to the new company, from fifteen employees in 1938 the firm ended the war with over 5,000, a significant producer of aircraft parts.

Notably, McDonnell produced the XF-85 Goblin aircraft and Mercury and Gemini spacecraft.