Megalotremis is a genus of lichen-forming fungi in the family Monoblastiaceae.

[1] It has 16 species.

[2] The genus was circumscribed by Dutch lichenologist André Aptroot in 1991, with Megalotremis verrucosa assigned as the type species.

Megalotremis is a pyrenolichen genus,[3] meaning its species have perithecioid ascocarps: spherical or flask-shaped, sessile or partly immersed in the thallus, with a single opening (ostiole) and enclosed by a distinct wall.

The species formerly known as Megalotremis endobrya (Döbbeler & Poelt) Aptroot (2008) is now Acrocordia endobrya.