The Solar Submillimeter Telescope (SST) is a solar telescope located at the Leoncito Astronomical Complex in San Juan Province, Argentina. The SST observes submillimeter radiation at 212 and 405 GHz using a 1.5-meter Cassegrain antenna. Radiation at these wavelengths is produced by high-energy particles during solar flares.
Construction of the SST started in 1995, and it achieved first light in April 1999. Since April 2001, it operates on a daily basis jointly by the Argentinian National Scientific and Technical Research Council (CONICET) and the Brazilian Mackenzie Presbyterian University.