Quercetin-3-O-β-D-galactopyranoside, is a hyperoside flavonol glycoside with anti-cancer, anti-inflammatory, and anti-oxidant activities that is derived from Hypericum and Crataegus plants. To this end, we examined the effect of this hyperoside in skin cancer cells lines and in DMBA/TPA induced skin tumors in vivo. In vitro treatment of cancer cells with hyperoside significantly inhibited phosphoinositide 3-kinase (PI3K)/protein kinase B (Akt)/mammalian target of rapamycin (mTOR)/p38 MAPK axis, concomitantly activated the 5'AMP-activated protein kinase (AMPK) signaling, inhibited proliferation, and induced apoptosis and autophagy. Hyperoside markedly inhibited diffuse epidermal hyperplasia and significantly reduced the changes in phosphorylated levels of PI3K, AKT, mTOR and AMPK while reducing p38 phosphorylation as well as of tumor burden in vivo in DMBA/TPA induced skin tumors. These data suggest that hyperoside might be of therapeutic value in chemoprevention of skin cancer.