Endometrial cancer (EC) presents a major global health challenge due to its heterogeneity and complex pathophysiology. The tumor microenvironment (TME), comprising stromal cells, immune cells, endothelial cells, and non-cellular components, critically influences EC progression. Single-cell RNA sequencing (scRNA-seq) has revolutionized our understanding of EC by revealing TME cellular heterogeneity and interactions. This review synthesizes recent scRNA-seq applications in EC, focusing on two key areas: ① Mapping transcriptional heterogeneity across major cellular components (epithelial, stromal, endothelial, and immune cells); ② Elucidating the factors driving tumor evolution, immune evasion, and differential immunotherapy response. Collectively, these scRNA-seq-derived insights into the dynamic TME ecosystem provide the foundation for translating basic discoveries toward clinical applications. Such advances could thereby promote TME-based personalized therapies and more accurate prognostic predictions.