The Shuttle–Mir program (Russian: Программа «Мир»–«Шаттл») was a collaborative space program between Russia and the United States that involved American Space Shuttles visiting the Russian space station Mir, Russian cosmonauts flying on the Shuttle, and an American astronaut flying aboard a Soyuz spacecraft to allow American astronauts to engage in long-duration expeditions aboard Mir.

The project, sometimes called "Phase One", was intended to allow the United States to learn from Russian experience with long-duration spaceflight and to foster a spirit of cooperation between the two nations and their space agencies, the National Aeronautics and Space Administration (NASA) and the Russian Space Agency (PKA). The project helped to prepare the way for further cooperative space ventures; specifically, "Phase Two" of the joint project, the construction of the International Space Station (ISS). The program was announced in 1993, the first mission started in 1994 and the project continued until its scheduled completion in 1998. Eleven Space Shuttle missions, a joint Soyuz flight and almost 1,000 cumulative days in space for American astronauts occurred over the course of seven long-duration expeditions. In addition to Space Shuttle launches to Mir the United States also fully funded and equipped with scientific equipment the Spektr module (launched in 1995) and the Priroda module (launched in 1996), making them de facto U.S. modules during the duration of the Shuttle-Mir program.

During the four-year program, many firsts in spaceflight were achieved by the two nations, including the first American astronaut to launch aboard a Soyuz spacecraft, the largest spacecraft ever to have been assembled at that time in history, and the first American spacewalk using a Russian Orlan spacesuit.

The program was marred by various concerns, notably the safety of Mir following a fire, a Russian spacecraft colliding with Spektr rendering it uninhabitable, financial issues with the cash-strapped Russian space program and worries from astronauts about the attitudes of the program administrators. Nevertheless, a large amount of science, expertise in space station construction and knowledge in working in a cooperative space venture was gained from the combined operations, allowing the construction of the ISS to proceed much more smoothly than would have otherwise been the case.

The origins of the Shuttle–Mir program can be traced back to the 1975 Apollo–Soyuz Test Project, that resulted in a joint US/Soviet mission during the détente period of the Cold War and the docking between a US Apollo spacecraft and a Soviet Soyuz spacecraft. This was followed by the talks between NASA and Intercosmos in the 1970s about a "Shuttle–Salyut" program to fly Space Shuttle missions to a Salyut space station, with later talks in the 1980s even considering flights of the future Soviet shuttles from the Buran programme to a future US space station – this "Shuttle–Salyut" program never materialized however during the existence of the Soviet Intercosmos program.

This changed after the Dissolution of the Soviet Union: the end of Cold War and Space Race resulted in funding for the US modular space station (originally named Freedom), which was planned since the early 1980s, being slashed. Similar budgetary difficulties were being faced by other nations with space station projects, prompting American government officials to start negotiations with partners in Europe, Russia, Japan, and Canada in the early 1990s to begin a collaborative, multi-national, space station project. In the Russian Federation, as the successor to much of the Soviet Union and its space program, the deteriorating economic situation in the post-Soviet economic chaos led to growing financial problems of the now Russian space station program. The construction of the Mir-2 space station as a replacement for the aging Mir became illusionary, though only after its base block, DOS-8, had been built. These developments resulted in bringing the former adversaries together with the Shuttle–Mir Program, which would pave the way to the International Space Station, a joint project with several international partners.

In June 1992, American President George H. W. Bush and Russian president Boris Yeltsin agreed to co-operate on space exploration by signing the Agreement between the United States of America and the Russian Federation Concerning Cooperation in the Exploration and Use of Outer Space for Peaceful Purposes. This agreement called for setting up a short, joint space project, during which one American astronaut would board the Russian space station Mir and two Russian cosmonauts would board a Space Shuttle.

In September 1993, American Vice-President Al Gore Jr., and Russian Prime Minister Viktor Chernomyrdin announced plans for a new space station, which eventually became the International Space Station. They also agreed, in preparation for this new project, that the United States would be heavily involved in the Mir project in the years ahead, under the code name "Phase One" (the construction of the ISS being "Phase Two").