Two unrecorded alien plants, Melilotus officinalis (L.) Lam. and M. indicus (L.) All. (Leguminosae) were found in Korea. M. officinalis is native to Eurasia and widely distributed in agricultural regions throughout the world. M. indicus is native to Mediterranean and Southwestern Europe, and naturalized in temperate regions all over the world. These species are morphologically similar to M. suaveolens (Jeon-dong-ssa-ri). However, M. officinalis is distinguished from M. suaveolens by transverse nerved legumes, definite ovary stalks, and five to eight number of ovules in ovary. M. indicus is also distinguished from M. suaveolens by smaller size of flowers, broadly triangular calyx teeth, globose legumes, and minutely papillose seeds. The local name of M. officinalis and M. indicus were given as “Ju-reumjeon- dong-ssa-ri” and “Jom-jeon-dong-ssa-ri” based on transverse nerved legumes and overall smaller size than M. suaveolens, respectively. The descriptions on morphological characters and photographs at the habitat of M. officinalis and M. indicus are provided.