The Nimbus satellites were second-generation U.S. robotic spacecraft launched between 1964 and 1978 used for meteorological research and development. The spacecraft were designed to serve as stabilized, Earth-oriented platforms for the testing of advanced systems to sense and collect atmospheric science data. Seven Nimbus spacecraft have been launched into near-polar, sun-synchronous orbits beginning with Nimbus 1 on August 28, 1964. On board the Nimbus satellites are various instrumentation for imaging, sounding, and other studies in different spectral regions. The Nimbus satellites were launched aboard Thor-Agena rockets (Nimbus 1–4) and Delta rockets (Nimbus 5–7).

Over a 20-year period from the launch of the first satellite, the Nimbus series of missions was the United States' primary research and development platform for satellite remote sensing of the Earth. The seven Nimbus satellites, launched over a fourteen-year period, shared their space-based observations of the planet for thirty years. NASA transferred the technology tested and refined by the Nimbus missions to the National Oceanic and Atmospheric Administration (NOAA) for its operational satellite instruments. The technology and lessons learned from the Nimbus missions are the heritage of most of the Earth-observing satellites NASA and NOAA have launched over the past three decades.