The genus Campylomyza Meigen, 1818, from the Micromyinae subfamily of the Cecidomyiidae, includes 40 known species globally. The genus Campylomyza has been primarily studied within the Palearctic region, with 39 species, 2 from the Nearctic region, and 1 from the Oriental region. As of now, four species have been documented in Korea: Campylomyza appendiculata, C. flavipes, C. furva, and C. spinata. Our research from 2017 to 2020 uncovered five previously unreported species in Korea (C. abjecta, C. aborigena, C. cornuta, C. cavitata, and C. cingulata) and introduces seven new species (C. angusta sp. nov., C. ambulata sp. nov., C. convexa sp. nov., C. cornigera sp. nov., C. hori sp. nov., C. odae sp. nov., and C. yeongyangensis sp. nov.). These findings are based on morphological evidence and DNA analysis. We present comprehensive data, including the mitochondrial COI sequences, diagnoses, detailed descriptions, and identification keys for these species. This work was supported by a grant from the National Institute of Biological Resources (NIBR), funded by the Ministry of Environment (MOE) of the Republic of Korea.