Specimens of the genus Orobdella Oka, 1895 from Korea, including various locations in the Korean Peninsula, were identified as Orobdella tsushimensis Nakano, 2011. Phylogenetic analyses using mitochondrial cytochrome oxidase subunit 1 (COI), ND1, $tRNA^{Cys}$, $tRNA^{Met}$, 12S rRNA, $tRNA^{val}$, and 16S rRNA markers show that the newly collected specimens form a monophyletic group with the known O. tsushimensis specimens. The genetic distance of COI of these specimens was in the range 0.4-6.6%. These results confirm that the newly collected specimens belong to O. tsushimensis. This is the first record of the genus Orobdella from the Korean Peninsula.