Endometrial cancer is one of the most common gynaecological cancers in developed countries, and the incidence is rising significantly. The staging of this disease is evolving from anatomic staging and risk stratification to a more molecular-based stratification. Treatment of endometrial cancer is also evolving. Paclitaxel plus carboplatin is the standard first-line chemotherapy for endometrial cancer; however, there is new evidence that the combination of chemotherapy and immunotherapy has synergistic effects in the treatment of this disease. This article discusses the latest advancements in endometrial cancer research in 2023, including highlights from the Society of Gynecologic Oncology (SGO) Annual Meeting on Women’s Cancers 2023 in March, the 2023 American Society of Clinical Oncology (ASCO) Annual Meeting in June, the 24th European Gynaecological Oncology (ESGO) Congress in September and October, and the European Society for Medical Oncology (ESMO) Congress 2023 in October. The article highlights the unprecedented progression-free survival (PFS) data from two Phase III randomised controlled trials evaluating first-line immunotherapy in combination with chemotherapy in patients with advanced or recurrent endometrial cancer: RUBY with dostarlimab, and NRG-GY018 with pembrolizumab, which created a buzz at SGO 2023 in the spring, and stimulated discussion throughout the remainder of the year. The overall survival (OS) results, the clinically meaningful benefits regardless of mismatch repair status, and health-related quality of life (QOL) in these studies are also discussed. Further topics covered in this year-in-review article include the implications of the results from RUBY and NRG-GY018 on first-line treatment and recurrent settings, and the effect of adding a poly adenosine diphosphate ribose polymerase (PARP) inhibitor to immunotherapy–chemotherapy combinations in the Phase III trial, DUO-E. Disparities in endometrial cancer care, research on fertility-sparing, and the importance of the multidisciplinary team (MDT) in endometrial cancer management are also explored. Following the announcement of practice-changing findings from RUBY and NRG-GY018 in March, data presented and published throughout the remainder of 2023 show that research in endometrial cancer continues at a pace.