The Sun Lounges were a fleet of three streamlined sleeper-lounge cars built by Pullman-Standard for the Seaboard Air Line Railroad (SAL) in 1956. The cars featured a distinctive glazed roof area meant to capture the ambience of a dome car in a lower profile, as tunnels on the East Coast of the United States prevented the use of dome cars there. The Seaboard employed all three Sun Lounges on its flagship Silver Meteor between New York City and Miami, Florida. The cars later saw service with the Seaboard Coast Line Railroad (SCL) and Amtrak. Two of the three survive in private ownership.

A dome car is a type of railway passenger car that has a glass dome on the top of the car where passengers can ride and see in all directions around the train. It also can include features of a coach, lounge car, dining car, sleeping car or observation. Beginning in 1945, dome cars were primarily used in the United States and Canada, though a small number were constructed in Europe for Trans Europ Express service.