The Suomi National Polar-orbiting Partnership or Suomi NPP, previously known as the National Polar-orbiting Operational Environmental Satellite System Preparatory Project (NPP) and NPP-Bridge is a weather satellite operated by the United States National Oceanic and Atmospheric Administration. Originally intended as a pathfinder for the NPOESS programme, which was to have replaced NOAA's Polar Operational Environmental Satellites and the US Air Force's Defense Meteorological Satellite Program, Suomi was launched in 2011 after the cancellation of NPOESS to serve as a gapfiller between the POES satellites and the Joint Polar Satellite System which will replace them. Its instruments provide climate measurements that continue prior observations by NASA's Earth Observing System.

The satellite is named after Verner E. Suomi, a meteorologist at the University of Wisconsin–Madison. The name was announced on January 24, 2012, three months after the satellite's launch.

The satellite was launched from Space Launch Complex 2W at Vandenberg Air Force Base in California by a United Launch Alliance Delta II 7920-10C on October 28, 2011. The satellite was placed into a sun-synchronous orbit 824 km (512 miles) above the Earth.