Human spaceflight programs have been conducted, started, or planned by multiple countries and companies. Until the 21st century, human spaceflight programs were sponsored exclusively by governments, through either the military or civilian space agencies. With the launch of the privately funded SpaceShipOne in 2004, a new category of human spaceflight programs – commercial human spaceflight – arrived. By the end of 2022, three countries (Soviet Union/Russia, United States and China) and one private company (SpaceX) had successfully launched humans to Earth orbit, and two private companies (Scaled Composites and Blue Origin) had launched humans on a suborbital trajectory.

The criteria for what constitutes human spaceflight vary. The Fédération Aéronautique Internationale defines spaceflight as any flight over 100 kilometers (62 mi). In the United States professional, military, and commercial astronauts who travel above an altitude of 80 kilometers (50 mi) are awarded the United States Astronaut Badge. This article follows the FAI definition of spaceflight.

Programs in this section are sorted by the years when the first successful crewed spaceflight took place.

The Vostok program was a project that succeeded in putting a person into orbit for the first time. Sergei Korolev and Konstantin Feoktistov began, in June 1956, crewed spacecraft research. The program developed the Vostok spacecraft from the Zenit spy satellite project and adapted the Vostok rocket from an existing ICBM design. Just before the first release of the name Vostok to the press, it was a classified word. By August/September 1958 a division had been formed devoted to producing the first Vostok craft. The official approval (decree) for the Vostok was delayed until 22 May 1959 by competition with photo reconnaissance programs.

Vostok 1 was the first human spaceflight. The Vostok 3KA spacecraft was launched on April 12, 1961, taking into space Yuri Gagarin, a cosmonaut from the Soviet Union. The Vostok 1 mission was the first time anyone had journeyed into outer space and the first time anyone had entered into orbit.

There were six Vostok flights in total, including the June, 1963 Vostok 6 mission flown by Valentina Tereshkova, the first woman in space. Another seven Vostok flights (Vostok 7 to 13) were originally planned, going through to April 1966, but these were canceled and the components recycled into the Voskhod program, which was intended to achieve more Soviet firsts in space.

Project Mercury was the first human spaceflight program of the United States. It ran from 1959 through 1963 with the goal of putting a human in orbit around the Earth. John Glenn's Mercury-Atlas 6 flight on 20 February 1962 was the first Mercury flight to achieve this goal. Prior to that, the Mercury-Redstone 3 mission brought the first American into space, Alan Shepard. It featured the first manual pilot control of the spacecraft and the landing with pilot still within it.

Early planning and research was carried out by the National Advisory Committee for Aeronautics, and the program was officially conducted by the newly created NASA.