Triclocarban (TCC), a widely used antibacterial agent, has aroused considerable public concern due to its potential toxicity. In the current study, we applied targeted metabolite profiling (LC/GC-MS) and untargeted H-1 NMR-based metabolomics in combination with biological assays to unveil TCC exposure-induced cellular metabolic responses in murine preadipocyte and human normal hepatocytes. We found that TCC promoted adipocyte differentiation in 3T3L1 preadipocytes, manifested by marked triglyceride (TG) and fatty acids accumulation, which were consistent with significant up-regulation of mRNA levels in the key adipogenic markers Fasn, Srebp1 and Ap2. In human hepatocytes (L02), TCC exposure dose-dependently interfered with the cellular redox state with down-regulated levels of antioxidant reduced-GSH and XBP1 and further induced the accumulation of TG, ceramides and saturated fatty acid (16:0). We also found that TCC exposure triggered unfold protein response (UPR) and endoplasmic reticulum (ER) stress in both cells through activation of ATF4 and ATF6, resulting in toxic lipid accumulation. These findings about lipid metabolism and metabolic responses to TCC exposure in both preadipocytes and hepatocytes provide novel perspectives for revealing the mechanisms of TCC toxicity.