Abstract Background International Cancer Benchmarking Partnership Module 4 reports the first international comparison of ovarian cancer (OC) diagnosis routes and intervals (symptom onset to treatment start), which may inform previously reported variations in survival and stage. Methods Data were collated from 1110 newly diagnosed OC patients aged >40 surveyed between 2013 and 2015 across five countries (51–272 per jurisdiction), their primary-care physicians (PCPs) and cancer treatment specialists, supplement by treatment records or clinical databases. Diagnosis routes and time interval differences using quantile regression with reference to Denmark (largest survey response) were calculated. Results There were no significant jurisdictional differences in the proportion diagnosed with symptoms on the Goff Symptom Index (53%; P = 0.179) or National Institute for Health and Care Excellence NG12 guidelines (62%; P = 0.946). Though the main diagnosis route consistently involved primary-care presentation (63–86%; P = 0.068), onward urgent referral rates varied significantly (29–79%; P < 0.001). In most jurisdictions, diagnostic intervals were generally shorter and other intervals, in particular, treatment longer compared to Denmark. Conclusion This study highlights key intervals in the diagnostic pathway where improvements could be made. It provides the opportunity to consider the systems and approaches across different jurisdictions that might allow for more timely ovarian cancer diagnosis and treatment.