NGC 2204 is an open cluster of stars in the Canis Major constellation.

Resolving the individual member stars is a challenge with a 10 to 12-inch amateur telescope.

[2] This is a rich but diffuse cluster with a Trumpler class of III 3m,[7][8] spanning a physical diameter of about 55 ly (17 pc).

[10] The metallicity is correspondingly poor,[11][8] showing an abundance of iron about 59% of that in the Sun.

[7] The cluster has a significant population of blue stragglers,[12][11] an indicator of past stellar mergers.