A luge is a small one- or two-person sled on which one sleds supine (face-up) and feet-first. A luger begins seated, propelling themselves initially from handles on either side of the start ramp, then steers by using the calf muscles to flex the sled's runners or by exerting opposite shoulder pressure to the pod. Racing sleds weigh 21–25 kg (46–55 lb) for singles and 25–30 kg (55–66 lb) for doubles. Luge is also the name of an Olympic sport that employs that sled and technique.

It is not to be confused with skeleton bob, which is also a single person tray-like sled in the Bobsleigh family, and the name of the sport that uses that sled, but which is designed for a running start, steering by shoulders and feet, and to be laid on face down and head first. While skeleton and bobsleigh are part of one international federation and sport, luge is organised separately by the International Luge Federation, FIL.

Lugers can reach speeds of over 140 km/h (87 mph), and is the fastest of the three 'sliding' sports. Austrian Manuel Pfister reached a top speed of 154 km/h (96 mph) on a track in Whistler, Canada, prior to the 2010 Winter Olympics. Lugers compete against a timer in one of the most precisely timed sports in the world—to one thousandth of a second on artificial tracks.

The first recorded use of the term "luge" dates to 1905 and derives from the Savoy/Swiss dialect of the French word luge, meaning "small coasting sled".