Objective <p>To investigate the anti-tumor and anti-angiogenic effects of diosgenin (Dio) in lung cancer.</p> Methods <p>Effect of Dio (0–50 µmol/L) on apoptosis and proliferation in non-small cell lung cancer (NSCLC) cells A549 and H1299 were evaluated by flow cytometry and colony formation assays. Transwell and angiogenesis experiments were used to assess Dio’s impact on vascular formation and migration of human wmbilical vein endothelial cells. Network pharmacology and molecular docking were combined to explore Dio’s anti-lung cancer mechanisms. Dio’s influence on Src/STAT3 pathway and angiogenic factors were evaluated by Western blot. C57BL/6 mice implanted with LLC cells and BALB/c-nu nude mice implanted with A549 cells (<i>n</i>=10 each group) were continuously treated with Dio (20 mg/kg) or solvent for 21 d to valid the anti-tumor efficacy of Dio.</p> Results <p>Dio effectively inhibited the growth of NSCLC cells <i>in vitro</i> and suppressed tumor angiogenesis (<i>P</i>&lt;0.01). Further network pharmacology analysis identified relevant pathways, and <i>in vitro</i> experiments confirmed that Dio exerted its anti-tumor effects and anti-angiogenic properties through Src/STAT3 pathway. It inhibits the synthesis and secretion of angiogenic factors vascular endothelial growth factor A, matrix metalloprotein-2, and -9. Additionally, the efficacy of Dio was inhibited by overexpression of STAT3. Finally, administration of Dio effectively suppressed the growth and angiogenesis of NSCLC tumors in mice (<i>P</i>&lt;0.01).</p> Conclusions <p>Dio potently inhibits tumor angiogenesis <i>in vitro</i> via Src/STAT3 pathway. It effectively attenuates tumor growth and suppresses angiogenesis <i>in vivo</i>. Given this, Dio is a promising anti-angiogenesis compound and might provide a novel strategy for the treatment of NSCLC.</p>