A suicide door is a car door hinged on the trailing edge, the edge closer to the rear of the vehicle. Such doors are rarely used on vehicles in modern times because of their disadvantages.

Although the term is often used in the custom car trade, it is avoided by major automobile manufacturers in favour of terms such as "coach doors" (Rolls-Royce), "FlexDoors" (Opel Meriva) "freestyle doors" (Mazda), "rear access doors" (Saturn Ion), and "rear-hinged doors".

Suicide doors were common on cars manufactured in the first half of the 20th century. In the era before safety/seat belts, the accidental opening of passenger doors, especially the front ones where the passenger's body was adjacent to the door, meant that there was a greater risk of falling out of the vehicle, than with front hinged doors where the airflow pushed the doors closed rather than opening them further. They were especially popular in the gangster era of the 1930s – supposedly because "It's a lot easier to shove somebody out with the wind holding the door open", as Dave Brownell, the former editor of Hemmings Motor News stated.