List of most massive star clusters

Below are lists of the most massive known star clusters in solar masses (M☉) and sorted in descending order.

Globular cluster masses can be determined by observing the proper motion of nearby stars influenced by the cluster[1][2] or by estimating the cluster's relaxation time.

[3] The masses of open star clusters can be estimated by measuring the falloff of radial and tangential velocities of surrounding stars at a particular distance.

[4]