Compositocoris senecionus, new genus and species, is described from the Namaqualand region of South Africa and assigned to the Halticini. Morphological documentation is provided in the form of colour habitus images, scanning electron micrographs for a suite of external characters for males and females, and line drawings of the male and female genitalia. Hosts are documented as annual species of Asteraceae, including Senecio laxus DC, Leysera tenella DC, and Ursinia sp.; digital colour images of hosts are included.