A frequently encountered scenario in gynecologic pathology is examination of the ovary via biopsy, cystectomy, or excision for ovarian enlargement, cyst formation, masses, torsion, or cases in which the ovary is submitted for evaluation for a clinical or radiological reason. Each of these settings requires the pathologist to have knowledge of the normal ovarian anatomy, the histology, and the range of nonneoplastic lesions of the ovary in order to guide the obstetrician-gynecologist or gynecologic oncologist to the appropriate treatment and follow-up. Various tumor-like conditions arising within the ovary may clinically simulate malignancy. In some cases, these present clinically as ovarian masses or ovarian cysts and raise concern for the presence of cancer or the lesions may themselves cause severe symptomatology that requires urgent treatment. Many of these conditions have characteristic clinical, gross, and histologic findings that often allow for precise classification by the pathologist.