Adult-type Granulosa cell tumor of the testis is a rare subtype of sex cord-stromal tumors, with fewer than 100 cases reported. The typical clinical presentation is an asymptomatic, painless testicular mass. We report a case of a 16-year-old male with adult-type testicular Granulosa cell tumor who presented with a palpable, painless right testicular mass, and subsequently underwent right inguinal radical orchiectomy. This report contributes to the growing body of literature regarding this rare diagnosis, furthering our understanding of clinical, imaging, and histological findings of its presentation.