Diorygma cameroonense is a little-known species of corticolous (bark-dwelling) script lichen in the family Graphidaceae.

This lichen is distinct due to its larger ascospores with more septa compared to the closely related Diorygma sticticum.

The type specimen was collected on 1 April 1999 in Bewala II Village near Ngatto, East Province, Cameroon, in a pristine rainforest along the Boumba River.

The lichen's fruit bodies are in the form of lirellae, which are single, unbranched or stellately to irregularly branched, and immersed to erumpent with a thick, complete thalline margin.

Diorygma cameroonense is distinguished from these species by its larger and more septate ascospores, as well as its unique chemistry.