Adipogenic differentiation is a highly regulated process that is necessary for metabolic homeostasis and nutrient sensing. The expression of PPAR and the subsequent activation of adipogenic genes is critical for the process. In this study, we identified lanthionine synthetase C-like protein 2 (LanCL2) as a positive regulator of adipogenesis in 3T3-L1 cells. Knockdown of LanCL2, but not LanCL1, inhibited adipogenic differentiation, and this effect was not mediated through cAMP or Akt signaling pathways. The expression of early adipogenic markers CCAAT enhancer binding protein β (C/EBPβ) and C/EBP remained intact in LanCL2 knockdown cells, but levels of late adipogenic markers PPAR and C/EBPα were suppressed. The addition of the naturally occurring PPAR activator 15-deoxy-12,14-prostaglandin J2 or conditioned medium from differentiating cells did not restore differentiation, implying that LanCL2 may not be involved in the production of a secreted endogenous PPAR ligand. Pulldown assays demonstrated a direct physical interaction between LanCL2 and PPAR. Consistent with a regulatory role of LanCL2, luciferase reporter assays revealed that full transcriptional activation by PPAR was dependent on LanCL2. Taken together, our study reveals a novel role of LanCL2 in adipogenesis, specifically involved in PPAR-mediated transactivation of downstream adipogenic genes.