The Mitsubishi Debonair is a four-door executive sedan introduced by Mitsubishi Motors in 1964 to serve as their flagship passenger vehicle in the Japanese market. The word "debonair" means gentle, courteous, suave, lighthearted, or nonchalant.

Executive car is a British term for a large car which is equivalent to the European E-segment and American full-size classifications. Executive cars are larger than compact executive cars, and smaller than luxury saloons / full-size luxury sedans.