Thunbergia grandiflorabelongs to the family Acanthaceae and is a widely distributed dicotyledonous plant in tropical and subtropical regions. Three isolates ofAllophoma(Dothideomycetes, Pleosporales, Didymellaceae) were collected from leaves ofT. grandiflorain Guangxi Province, China.Phylogenetic analyses of a combined ITS–LSU–rpb2–tub2dataset indicate that one of our three strains represents an undescribed species with close affinity toA. minorand the other two strains clustered amongst other isolates ofA. pterospermicola. Evidence from morphology and sequence analysis indicates that GUCC 2070.7 is a new species that we introduce here asA. thunbergiae. This is the first report about taxa ofAllophomafrom this host plant.