Background: PCOS, a common endocrine disorder, is linked to increased risks of endometrial cancer (EC) and ovarian cancer (OC). Our study utilizes bioinformatics analysis to identify shared gene signatures and elucidate biological processes between EC/OC and PCOS. Materials and Methods: Gene expression profiles for PCOS (GSE199225), endometrial cancer (GSE215413), and ovarian cancer (GSE174670) were obtained from the GEO database. Hub genes were identified through functional enrichment analysis and protein-protein interaction. Drug identification analyses were employed to find drugs targeting the hub genes. Result: Key hub genes linking PCOS and EC includes RECQL4, RAD54L, ATR, CHTF18, WDHD1, CDT1, PLK1, PKMYT1, RAD18, and RPL3; for PCOS and OC, they include HMOX1, TXNRD1, NQO1, GCLC, GSTP1, PRDX1, SOD1, GPX3, BOP1, and BYSL. Gene Ontology analysis revealed DNA Metabolic Processes in PCOS and EC, while in PCOS and OC, it identified the Removal of Superoxide Radicals. KEGG Pathway analysis highlighted Cell cycle in PCOS and EC and Hepatocellular carcinoma in PCOS and OC. Potential drugs for PCOS and EC include quercetin, calcitriol, and testosterone; for PCOS and OC, eugenol and 1-chloro-2,4-dinitrobenzene are identified. Conclusion: These findings offer insights into potential therapeutic targets and pathways linking PCOS with EC and OC, enhancing our understanding of the molecular mechanisms involved in these associations.