NGC 6535 is a globular cluster of stars located at a distance of 22,200 light years from Earth in the equatorial constellation of Serpens, and is listed in the New General Catalogue.

Its discovery is usually attributed to astronomer John Russell Hind in 1852.

[6][7] However, Wolfgang Steinicke has uncovered evidence that William Herschel's first discovery was actually NGC 6535, which he observed on 24 August 1780.

[4] The cluster is suspected to harbour an intermediate-mass black hole in its center.

[2] Unusually for a low-mass globular cluster, it has multiple generations of stars.