Calligrapha Chevrolat is a large American leaf beetle genus of imprecise taxonomic boundaries. Most species occur in Central and South America where they have not been subject to modern systematic revisions. This work is the first attempt to clarify the systematics of the group by focusing on a relatively diverse species group well characterized from a morphological standpoint: the group of C. argus Stål. I provide a pragmatic identification key for major lineages in Calligrapha, highlighting a potentially useful character for supra-specific rank systematics within this genus, namely the shape of the distal end of the flagellum in the penis. This key helps recognizing the C. argus species group as one with species having a single spot enclosed by humeral lunule and a complete arcuate band, laterally confluent with subsutural stripe (except in C. elegantula Jacoby), deep hypomeral furrow and with characteristic ventral carving at apex of flagellum, as major distinguishing features. The species group is subdivided into fourteen species, whereby one previously described taxon, C. famularis Stål, is subordinated as subspecies of C. geographica Stål stat. nov., and two new species from southern Mexico and Guatemala are described: C. anabelae sp. nov. and C. catarinae sp. nov. An identification key for all the species in the group is provided, as well as collection data for the approximately 2,100 specimens determined for this work and distribution maps based on these collection data. The group is centred in the Caribbean Mesoamerican biogeographic domain, with two species reaching the California-Rocky Mountain domain to the north (C. ancoralis Stål and C. diversa Stål), and three species reaching the Caribbean Northwest-South American domain to the south (C. argus Stål, C. diversa Stål and C. simillima Stål).