NGC 4861, also known as Arp 266, is a galaxy in the constellation Canes Venatici.

Its mass, size, and rotational velocity are consistent with it being a spiral galaxy.

[6] Two ultraluminous X-ray sources (ULXs) have been found within NGC 4861.

Assuming it is a star cluster, it has a mass of 400±80 M☉ and an age of 5 million years.

Compared to other star clusters with which ULXs are associated, its mass is quite low.