Background <p>Chidamide is a histone deacetylase inhibitor playing an anti-cancer role in several cancers. However, the function of chidamide in lung cancer remains to be further elucidated. This study was designed to explore the regulation of chidamide in glycolysis, ferroptosis, and chemosensitivity of cisplatin (DDP) in lung cancer, as well as its action mechanism associated with ubiquitin-specific protease 35 (USP35).</p> Methods <p>Cell viability and half maximal inhibitory concentration were examined using Cell Counting Kit-8 assay. Glycolysis metabolism was assessed through glucose uptake, lactate generation, and intercellular ATP level. Ferroptosis analysis was performed by detection of reactive oxygen species, glutathione and Fe²⁺ level. DDP sensitivity was evaluated by colony formation assay and flow cytometry. The protein expression was measured by Western blotting. The function of chidamide in mice was investigated using tumor xenograft assay.</p> Results <p>Lung cancer cell viability was decreased by chidamide. Chidamide resulted in glycolysis inhibition, ferroptosis promotion, and DDP sensitivity elevation of lung cancer cells. Chidamide could bind to USP35 and reduced its protein expression in lung cancer. The effects of chidamide on glycolysis, ferroptosis and DDP sensitivity were attributed to the downregulation of USP35. Chidamide reduced tumor growth in mice, and enhanced the sensitivity of tumors to DDP.</p> Conclusion <p>These findings proved that chidamide blocked lung cancer cell development and elevated DDP sensitivity via targeting USP35.</p>