Graphis khaoyaiensis is a rare species of corticolous (bark-dwelling) script lichen in the family Graphidaceae.

[1] Found only in a specific region in Thailand, it closely resembles Graphis dichotoma but can be distinguished by its smaller ascospores and the absence of radiately branched lirellae.

Graphis khaoyaiensis was formally described as a new species in 2019 by lichenologists Vasun Poengsungnoen and H. Thorsten Lumbsch.

The type specimen was collected at Pha Ta Bak waterfall in Khao Yai National Park, Thailand, on the tree bark of Castanopsis acuminatissima.

[2] Graphis khaoyaiensis has been found on the bark of Castanopsis acuminatissima trees in a tropical rainforest at Khao Yai National Park, Thailand.