Hyperandrogenism, insulin resistance, and acanthosis nigricans (HAIR-AN) is a severe subphenotype of polycystic ovary syndrome (PCOS). A 32-year-old woman with HAIR-AN and class 3 obesity presented to an endocrinology clinic after she failed sequential trials of treatment with metformin, estrogen–progestin OCP, spironolactone, leuprolide, and a levonorgestrel intrauterine device. She complained of hirsutism and acanthosis nigricans severely affecting her quality of life and had secondary amenorrhea. Laboratory evaluation showed extremely elevated testosterone and insulin levels and elevated glycated hemoglobin A1c (HbA1c). She underwent laparoscopic sleeve gastrectomy. One year after the surgery, she lost 32% of her body weight and reported normalization of menses, dramatic improvement in hirsutism, and near-resolution of acanthosis nigricans. Her testosterone, insulin, and HbA1c normalized. This case demonstrates the central role of hyperinsulinemia in HAIR-AN and suggests that aggressive measures to normalize insulin resistance and reduce excess weight can effectively treat the reproductive abnormalities in this syndrome. We suggest that bariatric surgery can be an effective cure for HAIR-AN syndrome and that PCOS, including HAIR-AN, should be considered a comorbidity of obesity during evaluation of bariatric surgery candidates.