Entoloma eugenei is a species of agaric (gilled mushroom) in the family Entolomataceae.

The species has a temperate distribution in the Russian Far East, Japan, and Korea, occurring mainly in mixed hardwood forests.Threats to its habitat have resulted in Entoloma eugenei being assessed as globally "endangered" on the IUCN Red List of Threatened Species.

[2] Molecular research, based on cladistic analysis of DNA sequences, has shown that it belongs in the subgenus Leptonia.

The cap surface is smooth, finely velvety when young, and deep blue.

The stipe (stem) is finely squamulose, cap-coloured or paler, lacking a ring.