KOMPSAT 3A (Korean Multi-purpose Satellite 3A) is a lightweight Earth observation satellite developed by the Korea Aerospace Research Institute KARI. It is similar to the KOMPSAT 3 spacecraft.

The optical component is being developed by Astrium. Additionally to its predecessor Kompsat-3, it carries also a infra-red instrument. Therfore the satellite bus was lengthend and the solar arrays enlarged. The imaging insrtrument has a resolution of 50 cm or less in visible band and 5.4 m in MWIR.

It operates at an altitude of 526 km × 540 km, 97°, in a sun-synchronous orbit for 4 years and monitor the Korean peninsula using a payload capable of submeter class resolution. The mission objectives of the KOMPSAT-3A are to provide continuous satellite Earth observation after KOMPSAT 1 and KOMPSAT 2 and to meet the nation's needs for high-resolution EO (Electro-Optical) images required for GIS (Geographical Information Systems) and other environmental, agricultural and oceanographic monitoring applications.