A new species of Cuspicona Dallas, 1851 (Pentatomidae: Pentatominae: Rhynchocorini) is described from eastern Australia. Cuspicona luedkei sp. n. is distinguished from congeners by the strongly produced mesosternal keel extending beneath the head, angulately produced laterotergite VII, spinose humeri, distinctive colour and punctation patterns, and genitalic characters. Adults, eggs, and nymphal instars I–III are described. Diagnostic characters, host associations, behavioural notes, and distribution are also documented. Integrative morphological and mitochondrial evidence (COI, 16S) supports placement of the new species within Cuspicona s. s. Phylogenetic analyses indicate that Cuspicona is not monophyletic and comprises multiple distinct lineages, with the Cuspicona simplex group forming a monophyletic lineage distinct from Cuspicona s. s. The classification of Cuspicona spp. and related genera within Rhynchocorini remains unresolved, requiring broader taxon sampling and additional loci in a comprehensive tribal revision.