Courtney A. O'Brien, DO

Dr. Courtney O’Brien is a board certified rheumatologist who practices in Simi Valley and Porter Ranch. She provides comprehensive care in general rheumatology with particular clinical interests in musculoskeletal ultrasound, osteoporosis, lupus, vasculitis, and inflammatory arthritis.

Dr. O’Brien earned her medical degree from Nova Southeastern University College of Osteopathic Medicine, where she received additional training in osteopathic manipulative medicine, emphasizing a holistic approach to patient care. Her passion for rheumatology was sparked early in her medical education through volunteer work with children affected by juvenile arthritis. She went on to complete her internal medicine residency at Rush University Medical Center in Chicago and her rheumatology fellowship at UCLA. She is certified in musculoskeletal ultrasound through the USSONAR program and integrates this advanced imaging technique into her clinical evaluations to ensure accurate and thorough diagnostic assessments.

Dr. O’Brien is also dedicated to global health and has participated in numerous medical outreach initiatives throughout Latin America and the Caribbean, delivering care to underserved populations. 

In her leisure time, Dr. O’Brien enjoys a variety of outdoor activities, including hiking, paddle boarding, skiing, roller skating, camping, and beach volleyball.