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. Morphological and mitochondrial evidence (COI, 16S) supports placement of the new species within Cuspicona s. s. Phylogenetic analyses indicate that Cuspicona may not be monophyletic, with the Cuspicona simplex group forming a distinct, strongly supported lineage separate from Cuspicona s. s. (which contains the type species Cuspicona thoracica (Westwood, 1837)). The classification of Cuspicona spp. and related genera within Rhynchocorini remains unresolved, requiring broader taxon sampling and additional loci in a comprehensive tribal revision.