The Couchette car (English and French usage, Italian: Cuccetta, German: Liegewagen) is a railroad car conveying basic sleeping accommodation.

The car is divided into a number of compartments (typically 8 or 9) accessed from the side corridor of the car, which in daytime are configured with a bench seat along each long side of the compartment. At an appropriate time in the journey, the attendant who travels in the car (or by agreement the passengers booked in the compartment) convert the compartment into its night-time configuration with two (1st class) or three (2nd class) bunks on each long side of the compartment. The attendant provides a sheet, blanket, and pillow for each passenger. Unlike in sleeping cars, couchette compartments are not segregated by sex, and it is normal not to undress except for removing footwear.

One compartment at the end of the car is reserved for the use of the attendant (who possibly supervises two adjacent cars), who will sell (if not included in the fare) hot and cold drinks and continental breakfasts in the morning. In western Europe the attendant will take charge of passenger's tickets and passports at the start of the journey, returning them before arrival at the destination, thus ensuring that passengers are not disturbed by ticket and passport inspections. In the former eastern bloc countries this is not done, and it is normal for passengers to be awakened before and after each border by each countries' border police and rail inspectors. Toilets and washrooms are located at the ends of the car.

N.B. Couchette cars have never been operated in Great Britain - it was normal practice for British passengers to join long-distance overnight trains at Calais, Boulogne, Oostende or Hoek van Holland after crossing the English Channel or North Sea by ferry. There has been a substantial decline in the number of long-distance overnight train services since the mid 1990s, caused by the increase in the number of high-speed daytime services, and competition from low-cost airlines.