Ovarian Cancer is a leading cause of mortality and morbidity, lacking clinical manifestations and effective early diagnostic techniques. The majority of cases are diagnosed at later stages; however, asymptomatic screening is currently not recommended due to its low predictive value and invasive nature. Furthermore, the current CA-125 biomarker used to monitor Ovarian Cancer is elevated in other conditions, including endometriosis or pelvic inflammation. Red Cell Distribution Width (RDW) is a parameter measured in a complete blood count, measuring the range of variation in red blood cell size and heterogeneity of red blood cell volume. RDW levels positively correlate with Ovarian Cancer progression, additionally increased in Ovarian Cancer groups compared to benign ovarian tumour groups. RDW possesses high sensitivity in distinguishing between cancerous and benign ovarian tumours, in line with ideal screening method standards. RDW additionally shows potential as a diagnostic biomarker in combination with other blood parameters, such as hemoglobin. The hemoglobin-RDW ratio (HRR) acts as an independent predictor of Ovarian Cancer stage. RDW’s mechanism of action is not fully elucidated but can be associated with iron/folic acid deficiency, ineffective hematopoiesis caused by chronic inflammation, or inflammatory cytokines such as IL-1 and IL-17. High RDW levels additionally possess prognostic value, acting as an indicator of low cumulative overall survival and poor chemotherapy responses in various cancers. Further research is needed on RDW’s mechanism of action and its implication as a marker in female cancers, particularly Ovarian Cancer, to implement effective early screening techniques and reduce fatalities.