A phaeton is a style of open automobile or carriage without weather protection. It is an automotive development of the fast, lightweight phaeton carriage. Originally meant to denote a faster and lighter vehicle than a touring car, the two terms eventually became interchangeable. A popular style of phaeton was the dual cowl phaeton, with a cowl separating the rear passengers from the driver and front passenger. A "victoria" carriage was easily adaptable to this type of vehicle.
Phaetons fell from favour when closed cars and convertible body styles became widely available during the 1930s. Convertibles and pillarless hardtops were marketed as "phaetons" after actual phaetons were phased out.
A phaeton differs from a convertible in having no winding or sliding windows in the doors or the body, and no permanent roof, whether rigid or folding. A detachable folding or rigid roof could be added before a drive in preparation for inclement weather, and side curtains or screens could be installed once the roof was in place. This was mainly temporary and partial relief rather than the more permanent, watertight protection offered by a convertible. As a result, a phaeton was much lighter than the sturdier, weather-ready convertible. Since the body was entirely open, it was easy to add or remove an extra row of seating where space had been left in the original construction.
The term phaeton had historically described a light, open four-wheeled carriage. When automobiles arrived it was applied to a light two-seater with minimal coachwork. The term was interchangeable with spyder, derived from a light form of phaeton carriage known as a spider. However, there were also double phaetons, with two rows of seats, triple phaetons, or even closed phaetons. Eventually, the term "phaeton" became so widely and loosely applied that almost any vehicle with two axles and a row or rows of seats across the body could be called a phaeton.
After 1912, American use of the term began to be most closely associated with the "triple phaeton" body configurations that had room for three ("rows" of) seats, whether all three were installed or not. Common usage further evolved to refer to a body with a rear seating area extended for added leg room or for an extra row of seating. This often gave the vehicle the appearance that it was meant to be chauffeur-operated. This also led to the term "phaeton" becoming similar to, and eventually interchangeable with, the term "touring car".