NGC 2804 is a lenticular galaxy in the constellation of Cancer. Its velocity with respect to the cosmic microwave background is 8580 ± 20 km/s, which corresponds to a Hubble distance of 126.55 ± 8.86 Mpc (∼413 million light-years). It was discovered by British astronomer John Herschel on 24 February 1827. This galaxy was also observed by the French astronomer Stéphane Javelle on 9 April 1896, and was later added to the Index Catalogue as IC 2455.

According to the SIMBAD database, NGC 2804 is a LINER galaxy, i.e. a galaxy whose nucleus has an emission spectrum characterized by broad lines of weakly ionized atoms.

One supernova has been observed in NGC 2804: SN 2023ftr (type Ia, mag. 18.51) was discovered by the Zwicky Transient Facility on 16 April 2023.

• List of NGC objects (2001–3000)

• Media related to NGC 2804 at Wikimedia Commons
• NGC 2804 on WikiSky: DSS2, SDSS, GALEX, IRAS, Hydrogen α, X-Ray, Astrophoto, Sky Map, Articles and images