Leiorreuma is a genus of script lichens in the family Graphidaceae.

[1] The genus was circumscribed by Franz Gerhard Eschweiler in 1824, with Leiorreuma hepaticum assigned as the type species.

It has apothecia with noticeable sessile opened lirellae.

The proper exciple is often thin on the sides but well-developed at the base and appears charred.

The hymenium is dotted with small specks, and the spores are pale brown and have thin walls with crosswise septa or are divided into many compartments (muriform).