Peritoneal tuberculosis (TB) is a rare extrapulmonary form of TB that often mimics ovarian malignancy, posing diagnostic challenges. This report presents a 16-year-old Jordanian female with abdominal distension, weakness, anorexia, and night sweats. Initial imaging, including contrast-enhanced computed tomography (CT), revealed compartmentalized ascites, peritoneal thickening, and enlarged ovaries with masses, suggesting possible ovarian malignancy. Laboratory findings showed elevated C-reactive protein (CRP) and cancer antigen 125 (CA-125) levels. The ascitic fluid analysis demonstrated high protein content with a neutrophil predominance, while pelvic magnetic resonance imaging (MRI) suggested tuberculous peritonitis. Exploratory laparotomy identified intra-abdominal adhesions, omental nodules, and a thickened peritoneum. Histopathology confirmed TB through granulomatous inflammation with caseating granulomas. This case underscores the importance of including TB in the differential diagnosis of ovarian malignancy, especially in TB-endemic areas, and highlights the role of early diagnosis and multidisciplinary management.