The Large Ultraviolet Optical Infrared Surveyor, commonly known as LUVOIR (/luːˈvwɑːr/), is a multi-wavelength space telescope concept being developed by NASA under the leadership of a Science and Technology Definition Team.

In 2019, the four teams turned in their final reports to the National Academy of Sciences, whose independent Decadal survey committee advises NASA on which mission should take top priority.

LUVOIR's multi-wavelength capability would also provide key information to help understand how a host star's UV radiation regulates the atmospheric photochemistry on habitable planets.

LUVOIR will also observe large numbers of exoplanets spanning a wide range of characteristics (mass, host star type, age, etc.

[1] The scope of astrophysics investigations include explorations of cosmic structure in the far reaches of space and time, formation and evolution of galaxies, and the birth of stars and planetary systems.

Furthermore, LUVOIR has an important role to play by studying plumes from the ocean moons of the outer Solar System, in particular Europa and Enceladus, over long timescales.

The LUVOIR technology development plan is supported with funding from NASA's Astrophysics Strategic Mission Concept Studies program, the Goddard Space Flight Center, the Marshall Space Flight Center, the Jet Propulsion Laboratory and related programs at Northrop Grumman Aerospace Systems and Ball Aerospace.

LUVOIR-A, previously known as the High Definition Space Telescope (HDST), was proposed by the Association of Universities for Research in Astronomy (AURA) on 6 July 2015.

[12] It would be composed of 36 mirror segments with an aperture of 15.1 metres (50 ft) in diameter, offering images up to 24 times sharper than the Hubble Space Telescope.

[12] The case for HDST was made in a report entitled "From Cosmic Birth to Living Earths", on the future of astronomy commissioned by AURA, which runs the Hubble and other observatories on behalf of NASA and the National Science Foundation.

[14] Ideas for the original HDST proposal included an internal coronagraph, a disk that blocks light from the central star, making a dim planet more visible, and a starshade that would float kilometers out in front of it to perform the same function.