Interleukins serve as communicating molecules between cells, mediating key interactions in the tumor microenvironment (TME) between immune cells and non-immune cells. Interleukin-10 (IL-10), a multifunctional cytokine with multiple properties, has been extensively studied in various aspects of immunology and cancer biology. IL-10 is pleiotropic, promotes cytotoxicity, yet inhibits antitumor-responses. In recent years, the role of IL-10 in ovarian cancer (OC) progression and treatment has gained significant scientific attention, elucidating the signaling pathways triggered by IL-10 action. OC, the leading cause of gynecologic cancer-related deaths, is characterized by ascites, which hosts an intricate TME that is not responsive to treatment by immune checkpoint inhibition. IL-10, known for its immunosuppressive and anti-inflammatory properties, plays a complex role in OC progression, immune modulation, and therapeutic response and has a potential therapeutic property as a target and as an effector. As the literature of basic science research studying the role of IL-10 in the TME of OC scopes a few decades and some data is contrasting, it is important to review the literature and provide concise input derived from it. This review aims to provide a comprehensive overview of the current understanding of IL-10 in OC, highlighting its influence on tumor growth, immune evasion, and potential as a therapeutic target.