The Marasmiaceae are a family of fungi in the order Agaricales.

Basidiocarps (fruit bodies) are most frequently agarics (gilled mushrooms), but occasionally cyphelloid (in the genus Cellypha).

According to a 2008 estimate, the family contained 54 genera and 1590 species,[1] but molecular research, based on cladistic analysis of DNA sequences, has led to a more restricted family concept,[2][3] so that the Marasmiaceae included just 13 genera,[4] and some 1205 species.

[5] It was reduced further down in 2020, to 10 genera and about 700 species.

[6] As accepted by Wijayawardene et al. 2020;[6]