A spaceport or cosmodrome is a site for launching or receiving spacecraft, by analogy to a seaport for ships or an airport for aircraft. The word spaceport—and even more so cosmodrome—has traditionally referred to sites capable of launching spacecraft into Earth's orbit or on interplanetary trajectories. However, rocket launch sites for sub-orbital spaceflights are also sometimes called spaceports, especially as new and proposed facilities for suborbital commercial spaceflight are often branded as "spaceports". Space stations and proposed future lunar bases are also sometimes referred to as spaceports, particularly when envisioned as nodes for further interplanetary travel.

Spaceports are evolving beyond traditional government-run complexes into multi-functional aerospace hubs, increasingly driven by private companies such as SpaceX, Blue Origin, and Virgin Galactic. A prominent example is Starbase, a private spaceport operated by SpaceX in Boca Chica, Texas. Starbase serves as the primary development and launch site for Starship, a fully reusable spacecraft designed for missions to the Moon, Mars, and beyond. The facility includes rocket production, launch, and landing infrastructure, and in May 2025, it was officially incorporated as a municipality in Texas—marking the first time a spaceport has become its own city. Starbase is now both a spaceport and a small residential and industrial community, primarily supporting SpaceX operations.

The term rocket launch site refers more broadly to any facility from which rockets are launched. Such facilities typically include one or more launch pads, often surrounded by a safety buffer called a rocket range or missile range, which includes the area rockets are expected to fly over and where components may land. These sites may also include tracking stations to monitor launch progress.

Major spaceports often feature multiple launch complexes, adapted for different launch vehicle types. For rockets using liquid propellants, storage and sometimes production facilities are necessary, while solid-propellant operations often include on-site processing. Some spaceports also incorporate runways to support horizontal takeoff and landing (HTHL) or horizontal takeoff and vertical landing (HTVL) vehicles.

In January 2025, traffic congestion was reported at U.S. rocket-launch sites due to the rising number of launches, primarily from companies like SpaceX, Blue Origin, and Virgin Galactic. Three sites in Florida and California currently handle most U.S. rocket launches.

The first rockets to reach space were V-2 rockets launched from Peenemünde, Germany in 1944 during World War II. After the war, 70 complete V-2 rockets were brought to White Sands for test launches, with 47 of them reaching altitudes between 100 km and 213 km.

The world's first spaceport for orbital and human launches, the Baikonur Cosmodrome in southern Kazakhstan, started as a Soviet military rocket range in 1955. It achieved the first orbital flight (Sputnik 1) in October 1957. The exact location of the cosmodrome was initially held secret. Guesses to its location were misdirected by a name in common with a mining town 320 km away. The position became known in 1957 outside the Soviet Union only after U-2 planes had identified the site by following railway lines in the Kazakh SSR, although Soviet authorities did not confirm the location for decades.

The Baikonur Cosmodrome achieved the first launch of a human into space (Yuri Gagarin) in 1961. The launch complex used, Site 1, has reached a special symbolic significance and is commonly called Gagarin's Start. Baikonur was the primary Soviet cosmodrome, and is still frequently used by Russia under a lease arrangement with Kazakhstan.