Intestinal microflora can influence abnormal adipocyte growth. Therefore, this study was aimed to investigate the probiotic properties and antioxidant and antiobesity effects of isolated strains from homemade kimchi. Among the isolated strains, Lactiplantibacillus plantarum KU15120 showed high tolerance to artificial gastric juice and bile salt conditions, high adhesion to HT-29 cells, nonproduction of β-glucuronidase, nonhemolysis, and acceptable resistance to antibiotics. It showed high antioxidant activity, including DPPH and ABTS radical scavenging and antioxidant activity, as determined by the β-carotene bleaching assay. Oil red O staining and intracellular triglyceride levels revealed reduced lipid accumulation, which confirmed the anti-adipogenic activity of L. plantarum KU15120. In addition, the expression levels of fatty acid synthase, CCAAT/enhance-binding proteinα, and peroxisome proliferator-activated receptorγ, were significantly lower in the probiotic-treated group than in the control group. These results suggest that L. plantarum KU15120 has probiotic properties, antioxidant, and antiobesity effects and could be used as a therapeutic probiotics.