This study aims to identify insect species relevant to medicolegal entomology in South Korea, to develop valuable forensic indicators for addressing legal challenges. We conducted carcass experiments with animals from 2015 to 2023 and analyzed domestic medicolegal literature. Species with uncertain taxonomic status or those recorded only once in experiments or literature were excluded. Our dataset includes observations from 185 carcasses, 24 criminal cases, and 468 autopsies. We identified a total of 254 carcass-associated species across 67 families and 8 orders. Of these species, 32 species consistently found on both human corpses and animal carcasses, suggesting their significance in forensic contexts. The order Diptera, comprising 53.13% of these taxa, was predominantly represented by the families Calliphoridae (70.59%), Muscidae (17.65%), and Sarcophagidae (11.76%). Coleoptera constituted 46.87% of the identified taxa, with the families Silphidae (53.33%), Dermestidae (26.67%), Cleridae (6.67%), Scarabaeidae (6.67%), and Staphylinidae (6.67%) being most significant. Lucilia sericata was the most frequently found species in autopsies of corpses found indoors (51.95%) and outdoors (14.77%), followed by Phormia regina, Chrysomya megacephala, Chrysomya pinguis and Lucilia illustris, highlighting their potential as forensic markers. This comprehensive study provides crucial baseline data for medicolegal entomologists in South Korea, identifying key insect species as forensic indicators.