NGC 654 is an open cluster in the constellation Cassiopeia.

It surrounds a 7th magnitude yellowish star, an F5Ia supergiant, which is a possible member of the group.

It is a very young cluster, aged approximately 15 million years, but it could be as old as 40 million years, with a time spread of star formation of at least ~20 Myr.

[5] One explanation is that between the Solar System and the cluster lie two dust layers, one at 200pc and one more at 1Kpc.

[7] NGC 654 is assumed to form part of the stellar association Cassiopeia OB8, that is located in the Perseus arm of the Milky Way, along with the open clusters M103, NGC 663, NGC 659, and some supergiant stars scattered between them, all of them having similar ages and distances.