The following species are recorded from the Comoro Islands for the first time: 12 species of Pentatomidae: Pentatominae—Anoano pronotalis Cachan, 1952 (from Mayotte), Antestiopsis clymeneis cf. galtiei (Frappa, 1934) (Mayotte), Bagrada hilaris (Burmeister, 1835) (Mayotte), Bathycoelia rodhaini Schouteden, 1913 (Mayotte), Coquerelia ventralis Horváth, 1904 (Mayotte), Eurysaspis transversalis Signoret, 1851 (Anjouan, Grande Comore, Mayotte), Gadarscama ebenaui Reuter, 1887 (Anjouan, Grande Comore, Mohéli, Mayotte), Lerida annulicornis (Signoret, 1861) (Anjouan, Mayotte), Neoacrosternum validum (Horváth, 1904) (Grand Comore, Mayotte), Nezara viridula (Linnaeus, 1758) (Mayotte), Piezodorus hybneri (Gmelin, 1790) (Mayotte), and Stenozygum mirabile (Signoret, 1861) (Mayotte); two species of Plataspidae—Brachyplatys hemisphaerica (Westwood, 1837) (Mayotte) and Coptosoma maculatum Westwood, 1837 (Mayotte); and one species of Scutelleridae—Hotea denticulata Stål, 1865 (Mayotte). The endemic pentatomine species Bathycoelia cuneifera Bergroth, 1893, syn. nov., is recognized as a junior subjective synonym of the widely distributed African species Bathycoelia thalassina (Herrich-Schäffer, 1844). The lectotype of B. cuneifera is designated herein. The checklist of the Pentatomoidea of Comoro Islands includes six species of Cydnidae, 21 species of Pentatomidae, two species of Plataspidae, one species of Scutelleridae and 1 species of Tessaratomidae. Of these species, six are endemic to the archipelago, 14 species are subendemic (shared with Madagascar and/or Aldabra Atoll), and nine species are widespread, occurring also on the African mainland (including the cosmopolitan pest Nezara viridula and two species of Bathycoelia Amyot & Serville, 1843 from the Guinean area, all three possibly alien to the archipelago). We document an additional eight species (six species of Pentatomidae, one species of each Scutelleridae and Tessaratomidae) that are identified to generic level only (two recorded from Grand Comore, seven from Mayotte, one of them occuring in both islands). Mayotte is the best sampled island, with 28 recorded species, followed by Grande Comore (11 species), Anjouan (six species), and Mohéli (four species). In addition the following new records are provided: Bathycoelia rodhaini from Cameroon, Central African Republic, Gabon and Zambia, Bathycoelia thalassina from Central African Republic and Ethiopia, and Piezodorus hybneri from Angola (Cabinda) and Sierra Leone. The type locality of Eurysaspis transversalis Signoret, 1851, India: Puducherry, is considered an error as the species occurs only in Madagascar and Comoros. The following plant associations are recorded from Mayotte: Bagrada hilaris on Cleome viscosa (Cleomaceae), Eurysaspis transversalis on Senna singueana (Fabaceae), and Piezosternum sp. on Cucumis sativus (Cucurbitaceae) and Mikania capensis (Asteraceae).