Various samples were collected from Korean islands in order to obtain unrecorded bacterial species in 2023. After aerobically incubating on marine agar and Reasoner’s 2A agar, approximately 1,200 bacterial strains were isolated and identified using 16S rRNA gene sequences. A total of 36 strains showed ≥98.7% sequence similarity to previously published and validated bacterial species. However, these strains have not previously been reported in the Republic of Korea, indicating that they belong to Korean unrecorded bacterial species. The unrecorded bacterial species were assigned to the classes Actinomycetes, Bacilli, Bacteroidia, Flavobacteriia, Sphingobacteriia, Alphaproteobacteria, Betaproteobacteria, and Gammaproteobacteria. The information we obtained by examining the strains includes details of the Gram reactions, colony and cell morphology, biochemical characteristics, and phylogenetic positions of the unrecorded species.