Katie O’Sullivan, MD

2025 Associate Junior Faculty Scholars

Katie O’Sullivan, MD, is a dual board-certified adult and pediatric endocrinologist who specializes in the care of children, adolescents, and young adults with endocrine disorders. Her clinical expertise includes type 2 diabetes, obesity, polycystic ovary syndrome (PCOS), thyroid disease, and endocrine complications related to cancer immunotherapy. Dr. O’Sullivan serves as Endocrinology Clinic Director at UChicago Medicine Orland Park and leads several multidisciplinary programs, including collaborative clinics for patients with celiac disease and endocrine conditions, as well as an adolescent and young adult PCOS clinic.

In addition to her clinical work, Dr. O’Sullivan is an educator and researcher committed to improving outcomes for patients with endocrine and metabolic disorders. Her research has focused on youth-onset type 2 diabetes, obesity, sleep-related metabolic health, and barriers to care for patients with diabetes and celiac disease. She has published in leading journals and has been invited to speak nationally on the interdisciplinary management of youth-onset type 2 diabetes.

Dr. O’Sullivan is deeply involved in medical education, serving as Director of the Endocrinology Module in the Pritzker School of Medicine curriculum and Assistant Program Director for recruitment in the Pediatric Endocrinology Fellowship. She is passionate about mentoring trainees and advancing high-quality, patient-centered endocrine care across the lifespan.