Objective: This study aimed to comprehensively evaluate the expression patterns, prognostic significance, and functional roles of Cyclin-Dependent Kinases (CDKs) in breast cancer. Methods: Transcriptional profiles of CDK family members in breast cancer were systematically interrogated using the Oncomine database. Prognostic correlations between CDK expression and clinical outcomes were evaluated through Kaplan-Meier survival analysis via the Kaplan-Meier Plotter platform. Tumor stage-dependent expression patterns of CDKs were assessed using the GEPIA database. Functional enrichment analysis of CDK-associated pathways, including DNA replication and cell cycle regulation, was performed using the KEGG pathway database. Genetic co-expression networks and potential regulatory interactions among CDKs were investigated using the cBioPortal platform. Additionally, miRNA-mediated posttranscriptional regulation of CDKs was predicted using the ENCORI database. Results: Oncomine revealed significant upregulation of CDK1, CDK5, and CDK20 and downregulation of CDK2/CDK6 in tumors. GEPIA identified elevated CDK1, CDK5, and CDK20 expression in advanced tumor stages. Kaplan-Meier analysis associated high CDK1, CDK3, CDK4, and CDK20 with reduced overall survival, while CDK8 correlated with progression risk. KEGG implicated CDKs in cell cycle regulation, and ENCORI predicted 12 miRNAs targeting CDKs. Conclusion: CDK1, CDK3, CDK4 and CDK20 have great potential to become valuable biomarkers for prognosis of breast cancer.