New records are presented for 23 Australian species of the family Cydnidae (Pentatomoidea). Alonips papuanus is documented for the first time in Australia. The first precise localities for Aethus parvulus in Australia are provided. Additionally, five species are reported as new records for Australian states and territories. These are Byrsinus ochraceus (new to Northern Territory, Victoria, Queensland, and Western Australia), Byrsinus setosus (new to Western Australia), Fromundus pygmaeus (new to Queensland), Geotomus breweri (new to New South Wales, Northern Territory, and Victoria), and Geotomus gracilipes (new to Victoria).