Six new species of Graphidaceae are described from Sri Lanka, four in Graphis sensu Staiger and one each in Fissurina and Thelotrema. Fissurina srilankensis Weerakoon, Wijeyaratne & Lücking is characterized by lirellae with well-developed labia and comparatively large, muriform ascospores. Graphis allugallenensis Weerakoon, Wijeyaratne & Lücking is similar to G. vittata but has a distinctly verrucose thalline margin along the lirellae. Graphis dotalugalensis Weerakoon, Wijeyaratne & Rivas Plata resembles G. proserpens in the exposed lirellae with striate labia and apically carbonized excipulum but differs in the comparatively large ascospores. Graphis knucklensis Weerakoon, Wijeyaratne & Wolseley features lirellae with striate labia, an inspersed hymenium, and norstictic acid as secondary compound. Graphis srilankensis Weerakoon, Wijeyaratne & Lumbsch has entire labia with a completely carbonized excipulum, inspersed hymenium, transversely septate ascospores, and produces norstictic acid. Finally, Thelotrema pseudosimilans Weerakoon, Wijeyaratne & Lumbsch is close to T. similans in the corticate thallus and prominent apothecia with narrow pore, but has consistently larger ascospores.