NEO Surveyor, formerly called Near-Earth Object Camera (NEOCam), then NEO Surveillance Mission, is a planned space-based infrared telescope designed to survey the Solar System for potentially hazardous asteroids.

The NEO Surveyor spacecraft will survey from the Sun–Earth L₁ (inner) Lagrange point, allowing it to see objects inside Earth's orbit, and its mid-infrared detectors sensitive to thermal emission will detect asteroids independently of their reflected sunlight. The NEO Surveyor mission will be a successor to the NEOWISE mission, and the two missions have the same principal investigator, Amy Mainzer at the University of Arizona.

Since first proposed in 2006, the concept repeatedly competed unsuccessfully for NASA funding against science missions unrelated to planetary defense, despite an unfunded 2005 US Congressional directive to NASA. In 2019, the Planetary Defense Coordination Office decided to fund this mission outside NASA's science budget due to its national security implications. On 11 June 2021, NASA authorized the NEO Surveyor mission to proceed to the preliminary design phase. The Jet Propulsion Laboratory will lead development of the mission.

As of December 2022, NEO Surveyor is expected to be launched no later than June 2028. As of February 2025, it will be launched on a SpaceX Falcon 9 from Florida in September 2027.

In 2005, the U.S. Congress mandated NASA to achieve by the year 2020 specific levels of search completeness for discovering, cataloging, and characterizing dangerous asteroids larger than 140 m (460 ft) (Act of 2005, H.R. 1022; 109th), but it never appropriated specific funds for this effort. NASA did not prioritize this unfunded mandate, and directed the NEOCam project to compete against science missions for general funds not earmarked for planetary defense and disaster mitigation planning.

Proposals for NEOCam were submitted to NASA's Discovery Program in 2006, 2010, 2015, 2016 and 2017, but each time were not selected for launch. The mission concept nonetheless received technology development funding in 2010 to design and test new infrared detectors optimized for asteroid and comet detection and sizing. The project received additional funding for further technological development in September 2015 (US$3 million), and in January 2017.

Following calls to fully fund the mission outside NASA's Planetary Science Division or directly from Congress itself, NASA's associate administrator for science announced on 23 September 2019 that instead of competing for funding, NEOCam will be implemented under the name NEO Surveillance Mission with budget from NASA's Planetary Defense Coordination Office, within the Planetary Science Division. The near-miss of asteroid 2019 OK, which slipped past extant detection methods in July 2019, has been suggested to have helped prompt this decision.

For funding and management purposes, the NEO Surveillance Mission is officially a new project, but it is the same space telescope, the same team, and the mission's goals remain unchanged.