Space Center Houston is a science museum that serves as the official visitor center of NASA Johnson Space Center in Houston, Texas. It was designated a Smithsonian Affiliate museum in 2014. The organization is not owned by NASA and does not receive federal funds -- it is the cornerstone project of the nonprofit Manned Space Flight Education Foundation, a 501(c)(3) organization. The center does have a strong partnership with NASA Johnson Space Center, the home of Mission Control and astronaut training, which affords the center access to tour the grounds and some buildings with the general public.

The center opened in 1992 replacing the former Visitor Center in Johnson Space Center Building 2. The museum is 250,000 square feet (23,000 m²) and displays over 400 space artifacts, including the Mercury 9, Gemini 5, and Apollo 17 flown space capsules and the only space shuttle visitors can walk inside.

This artifact gallery includes three flown spacecraft, several used in training, and a display of Moon rocks:

Space Center Houston is the home of the Independence Plaza exhibit complex. This attraction contains the world's only high-fidelity Space Shuttle replica, where it stands mounted on one of the two original shuttle carrier aircraft. Independence Plaza is the only place where the public can enter both vehicles. The Space Shuttle replica Independence, formerly known as Explorer, was previously located at Kennedy Space Center Visitor Complex, but was moved to make way for a new permanent attraction hall for Space Shuttle Atlantis. Independence is now displayed atop the retired Shuttle Carrier Aircraft, NASA 905. On August 14, 2014, a heavy lift called The Rise of Independence was completed to place Independence on top of NASA 905. The plane was transported to Space Center Houston from Ellington Airport on April 30, 2014.

Space Center Houston was briefly considered as a home for one of the retired Space Shuttle orbiters, but the Kennedy Space Center Visitor Complex, Intrepid Sea, Air and Space Museum, and California Science Center were instead selected. A NASA report showing the final scoring showed Space Center Houston finished 10th among 13 museums competing for the three orbiters (not already committed to the Smithsonian Air and Space Museum).

A Falcon 9 Full Thrust booster B1035 is displayed near Independece Plaza since March 2020. The booster was used twice in ISS cargo missions CRS-11 and CRS-13 by NASA before retirement.

Of the three remaining Saturn V rockets on display, only the one at the Johnson Space Center is made up of segments originally intended for flight. The first stage of this Saturn V rocket is from SA-514 (originally intended for the cancelled Apollo 19), the second stage from SA-515 (originally intended for the cancelled Apollo 20), and the third stage from SA-513, which was not needed after it was replaced by the Skylab workshop. SA-513 was originally scheduled for the cancelled Apollo 18 – the rest of the rocket was used for Skylab. The Apollo Command/Service Module CSM-115a (intended for Apollo 19) completes the rocket as it would stand on the launchpad.

The Saturn V, on loan from the Smithsonian, was displayed outside the Johnson Space Center main entrance from 1977 through 2004. Grants from the National Park Service's Save America's Treasures program, the National Trust for Historic Preservation and private contributors funded the restoration by Conservation Solutions of Washington DC with oversight by the Smithsonian.