NGC 6646 is a spiral galaxy located in the constellation Lyra. Its velocity relative to the cosmic microwave background is 5,641 ± 35 km/s, which corresponds to a Hubble distance of 83.2 ± 5.9 Mpc (~271 million ly). NGC 6646 was discovered by German-British astronomer William Herschel on 26 June 1802. The luminosity class of NGC 6646 is I.
One supernova has been observed in NGC 6646: SN2024gqf (TypeIa, mag. 19.7) was discovered by the Catalina Real-time Transient Survey (SNHunt) on 15 April 2024.