Leucocoprinus griseofloccosus is a species of mushroom producing fungus in the family Agaricaceae.

[1][2] It was first described in 2018 by the French mycologists Vincent Lagardère & Guillaume Eyssartier from specimens found in 2017 in Mouréou, Arengosse in the South West Landes region of France.

[3] The specimens in France were found growing within rotting alder trunks beside a stream in mixed woodland.

[3] In November 2019 it was found in the UK for the first time with specimens observed to be growing in rotten Douglas fir logs at the New Forest Reptile Centre near Lyndhurst, South Hampshire.

Another observation was made in October 2020 on rotting pine logs in Marlhill copse near Southampton airport.