Purpose <p>Currently, there is controversy surrounding the association between dietary fatty acids (FAs) and ovarian cancer (OC) risk. We aimed to elucidate the aforementioned topic using data from a large cohort.</p> Methods <p>Women participating in the Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial were included in this study. The dietary information of participants was collected through the diet history questionnaire. Multivariable Cox proportional hazards regression models incorporating restricted cubic splines were constructed to explore the association between dietary FAs intake and the incidence of OC.</p> Results <p>Among 50,614 participants in the present study, a total of 277 cases of ovarian cancer were diagnosed. The median follow-up time was 9.44 years. Non-significant association between total FAs intake and risk of OC was observed (non-linear <i>P</i> = 0.060). Compared to the median of total FAs intake, hazard ratios were 1.68 (95% CI: 1.10–2.58) and 1.45 (95% CI: 1.05–1.99) for the 5th percentile and 10th percentile, respectively, while consuming more than the median failed to show significant findings. Similar results were found in the analyses of different types (saturated fatty acids, monounsaturated fatty acids, and polyunsaturated fatty acids) and sources (animals and plants) of dietary FAs.</p> Conclusion <p>Inadequate consumption of various types and sources of dietary FAs might be associated with an increased risk of OC.</p>