Cosi, COSI or CoSi may refer to:

• Così, a 1992 play by Louis Nowra
  • Cosi (film), 1996, based on the play
• Così (restaurant), an American fast-casual restaurant chain
• Compton Spectrometer and Imager, or COSI, a NASA telescope to be launched in 2025
• COSI (Center of Science and Industry), a science museum and research center in Columbus, Ohio, U.S.
• COSI Toledo, now Imagination Station, a science museum in Toledo, Ohio, U.S.
• Cobalt monosilicide, a material with the chemical formula CoSi
• Julián Cosi (born 1998), an Argentine footballer
• Valerio Cosi (born 1985), an Italian musician

• All pages with titles containing Cosi
• Così fan tutte (disambiguation)
• Così è (se vi pare) (disambiguation)