ABSTRACT Introduction: The incidence of endometrial cancer in low-income countries is rising at a rapid rate. This could be due to changes in risk factors and socio-economic transitions occurring in developing countries. The main aim of this study was to assess the changes in endometrial cancer incidence in Sri Lanka. Materials and Methods: Incidence data for uterine corpus cancer and endometrial cancer between 2011 and 2020 were extracted from the National Cancer Register of Sri Lanka. This included the crude rate, age standardised incidence rate, and age-specific incidence. Joinpoint trend analysis software was used to analyse the temporal pattern of incidence. The estimated annual percentage change of incidence (EAPC) was calculated Results: A total of 8332 patients with uterine corpus cancer were reported with the highest incidence in the 60–70-year-old age group. The EAPC of uterine corpus cancer was 9.26%, while it was 8.26% for endometrial cancer. The highest rise of age-specific incidence was observed in the 70 years plus age group (EAPC 13.3968%, 95% confidence interval (CI): 9.6916–17.1994). Conclusion: There is a clear rise in endometrial and uterine cancer incidence in Sri Lanka. While part of this could be due to better reporting of new cases, a true increase in incidence should have occurred due to different rates of EAPC among age categories. Studies to evaluate the factors leading to the rising incidence of endometrial cancer are recommended.