Nimbus 4 (or Nimbus-D) was a meteorological satellite launched by NASA into a Sun-synchronous near-polar orbit on April 8, 1970. It was the fourth in a series of second-generation meteorological satellites in the Nimbus program. 

Nimbus 4 was designed to serve as a stabilized, Earth-oriented platform for the testing of advanced meteorological sensors and the collection of meteorological data. The spacecraft carried the following experiments:

• Backscatter Ultraviolet (BUV)
• Filter Wedge Spectrometer (FWS)
• Image Dissector Camera System (IDCS)
• Infrared Interferometer Spectrometer (IRIS)
• Interrogation, Recording, and Location System (IRLS)
• Monitor of Ultraviolet Solar Energy (MUSE)
• Satellite Infrared Spectrometer (SIRS)
• Selective Chopper Radiometer (SCR)
• Temperature-Humidity Infrared Radiometer (THIR)

The spacecraft performed well until April 14, 1971, when attitude problems started. The experiments then operated on a limited basis until September 30, 1980.