Ovarian cancer (OC) is the most lethal gynecologic malignancy, characterized by multiple histological subtypes, each with distinct pathological and clinical features. Current treatment approaches include cytotoxic chemotherapies, poly(ADP-ribose) polymerase (PARP) inhibitors, bevacizumab, hormonal therapy, immunotherapy, and antibody-drug conjugates (ADCs). In this review we discuss immune evasion mechanisms in OC and the role of genetics, the tumor microenvironment, and tumor heterogeneity in influencing these processes. We also discuss the use of immunotherapies for OC treatment, either alone or in combination with other anticancer agents, with a focus on their clinical outcomes. Finally, we highlight emerging immunotherapies that have either succeeded or are on the verge of significantly impacting cancer treatment, and we discuss their potential utility in the effective treatment of OC.