Synthetic musk compounds (SMCs) and benzotriazole ultraviolet stabilizers (BUVSs) are used as additives in many consumer products. Limited data are available on the accumulation of SMCs in human fluids, and no data are available on BUVSs. In this study, 208 human breast milk samples were collected from 87 participants during the lactation period at <7, 15, 30, and 90 days after delivery in Korea. The total concentrations of SMCs and BUVSs ranged from <LOQ to 1593 (median: 286) ng/g lipid weight and from <LOQ to 2172 (median: 64.7) ng/g lipid weight, respectively. The residue levels of HHCB and AHTN in our samples were the highest, compared to those reported in the US, Europe, and China. The predominant compounds were HHCB and AHTN for SMCs and UV-328 for BUVSs, consistent with consumption patterns of these contaminants. Over the lactation period, no significant changes were found in concentrations of SMCs and BUVSs for both parity groups. Maternal age, body mass index, and parity were not associated with the concentrations of SMCs and BUVSs, while gestational age and delivery mode were associated with these contaminants. The estimated daily intakes of HHCB and AHTN were lower than the provisional tolerable daily intake values, suggesting a limited health risk to Korean infants. This study is the first to comprehensively investigate the current levels, accumulation features, contributing factors of BUVSs associated with breast milk consumption in Korea.