The Smithsonian Astrophysical Observatory (SAO) is a research institute of the Smithsonian Institution, concentrating on astrophysical studies including galactic and extragalactic astronomy, cosmology, solar, earth and planetary sciences, theory and instrumentation, using observations at wavelengths from the highest energy gamma rays to the radio, along with gravitational waves.

Charles Greeley Abbot was named SAO's first director, and the observatory operated solar telescopes to take daily measurements of the Sun's intensity in different regions of the optical electromagnetic spectrum.

It is likely that SAO's early history as a solar observatory was part of the inspiration behind the Smithsonian's "sunburst" logo, designed in 1965 by Crimilda Pontes.

Following the launch of Sputnik (the world's first human-made satellite) in 1957, SAO accepted a national challenge[3] to create a worldwide satellite-tracking network, collaborating with the United States Air Force on Project Space Track.

In addition, the SAO has about 120 postdoctoral researchers/fellows working in five competitive, associated fellowship programs: CfA, Clay, SMA, ITAMP, and Leon Van Speybroeck, or in support of a contract or grant.