Background: The transcription factors Forkhead box protein O1 (FOXO1) and paired box 3 (PAX3) are involved in various cellular functions and oncogenesis. In this study, we aimed to determine their involvement in high-grade serous ovarian cancer (HGSOC) through immunohistochemical expression. Methods: Immunohistochemical analysis was performed on 128 paraffin-embedded specimens of HGSOC to evaluate the expression of FOXO1 and PAX3. The data were correlated with various clinicopathological variables. Results: FOXO1 and PAX3 were expressed in a significant proportion of cancer tissues, 90% and 59%, respectively. The Kaplan-Meier plots indicated that patients who exhibited positive FOXO1 expression had better overall survival (OS) and disease-free survival (DFS) rates. Patients with positive PAX3 expression had a slightly shorter overall survival period. Chemoresistance and advanced International Federation of Gynecology and Obstetrics (FIGO) stage were found to have the strongest association with poorer survival. Conclusions: We found an increased immunohistochemical expression of PAX3 and FOXO1 in HGSOC. This finding indicates a need for deeper exploration of their links to signalling pathways, which could lead to the development of new therapeutic strategies to combat chemoresistance.