Abnormal melanin synthesis upon UV exposure causes excessive oxidative stress, which leads to skin hyperpigmentation disorders such as freckles, melisma, and age spots. The present study investigated the anti-melanogenic effects of decursin and the underlying mechanism using multiple approaches. Decursin exhibited no cytotoxicity and significantly reduced intracellular tyrosinase activity and melanin content in B16F10 melanoma cells. Decursin also inhibited the expression of melanogenic enzymes such as tyrosinase and tyrosinase-related protein (TRP)− 1, but not TRP-2. Mechanistically, decursin suppressed melanin synthesis through cAMP-dependent protein kinase (PKA)/cAMP response element-binding protein (CREB)-dependent downregulation of microphthalmia-associated transcription factor (MITF), a master transcription factor in melanogenesis. Further, decursin exerted anti-melanogenic effects by downregulating the p38 signaling pathway and upregulating extracellular signal-regulated kinase (ERK) and phosphatidylinositol 3 kinase (PI3K)/protein kinase B (Akt)/glycogen synthesis kinase-3β (GSK-3β) cascades. in silico analysis showed that decursin formed specific interactions with residues of upstream regulators of MITF and exhibited optimal pharmacokinetic profiles, including permeability and skin sensitization. Finally, the anti-melanogenic effects of decursin were confirmed ex vivo in 3D human skin models, suggesting its applicability as a protective agent against hyperpigmentation.