Objective: To examine clinical trends in Denmark for younger and older epithelial ovarian cancer (EOC) patients, focusing on incidence, treatment, and survival changes. Methods: We included a nationwide cohort diagnosed with EOC from 2005 to 2018. We described age-standardized incidence, surgical patterns, residual disease trends, and cancer-specific survival stratified by age (<70 and ≥ 70 years), stage, and period (2005–09, 2010–13, 2014–18). Results: We included 7522 patients. The incidence decreased from 16.3 (2005) to 11.4 (2018) per 100,000 woman-years, driven by the younger cohort. While the proportion of patients with stage IIIC-IV disease undergoing primary debulking surgery (PDS) decreased, the proportion of patients having interval debulking surgery (IDS) and no debulking surgery increased significantly. In 2014–18, 36% and 24% had PDS for younger and older patients, respectively, compared to 72% and 62% in 2005–09. In both age cohorts, the proportion of patients debulked to no residual disease increased significantly among patients with stage IIIC-IV and in the total cohort. Two-year cancer-specific survival increased from 75% (2005–09) to 84% (2014–18) for younger patients and from 53% to 66% for older patients. After adjusting for potential confounders, age ≥ 70 was associated with a 1.4-fold increased risk of cancer-specific death (95% confidence interval: 1.2,1.5). Conclusions: The proportion of patients with advanced EOC not undergoing PDS or IDS increased significantly. During the same period, patients debulked to no residual disease, and cancer-specific survival increased. However, a survival gap in favor of the younger patients remains after adjusting for potential confounders.