Inguinal ovarian hernia in adult women is rare, and cases concomitant with adenomyoma of the uterine round ligament are even rarer. Here, we report the diagnostic and therapeutic course of a 49-year-old woman with a right-sided inguinal ovarian hernia complicated by adenomyoma of the round ligament. We further analyzed this case in conjunction with the literature, with a focus on the clinical characteristics, diagnosis, and management of adult inguinal ovarian hernia. Preoperative diagnosis remains challenging, and the condition is prone to misdiagnosis or missed diagnosis. Imaging modalities such as ultrasonography, computed tomography, or magnetic resonance imaging demonstrating an "absent" ipsilateral ovary can facilitate the diagnosis. Surgery is the mainstay of treatment. Intraoperatively, particular attention should be paid to preserving the ovary and reproductive function, and hernia repair should be performed to prevent postoperative recurrence.