The Sulaco is a spaceship shown in the movie Aliens and briefly in Alien3. Her name comes from a fictional port in Joseph Conrad's novel Nostromo. Used by the United States Colonial Marines, the Sulaco is a Conestoga-class starship, originally designed as troop and logistics transports. By 2179, these ships had been converted into a rapid-response military transport, with orbital bombardment and fleet support capabilities. The Sulaco masses 78,000 metric tons and measures 385 meters (1,263 feet, almost a quarter-mile) in length. In her role as a troop carrier, Sulaco carries two UD4L Cheyenne dropships and has sufficient life support capabilities for 90 crew and passengers. In an emergency, as many as 2,000 troops can be placed in hibernation in the main cargo hangars. She is powered by a 3.6 terawatt fusion reactor using high density lithium hydride for fuel. Sublight propulsion is provided by four GF-2400 rocket motors using industrial carbon-diamond as reaction mass. Faster-than-light propulsion is provided by a hyperdrive tachyon shunt, with a maximum speed of 0.74 light years per sidereal day. The Sulaco's hull panels are constructed from radar absorbing material, which reduces the ship's radar cross section to low levels.

Syd Mead, a principal conceptual designer on Aliens, first designed the Sulaco as a massive sphere, bristling with antennae. Director James Cameron was not satisfied; he sketched the "style" of ship he imagined, which was more like a streamlined warship plying the black. Syd's subsequent redesign is what we see on screen: he maximized Cameron's direction, making the Sulaco essentially an enlarged version of a pulse rifle.