Dr. Jo A. Hannafin is board certified in orthopedic surgery and sports medicine. She is an Attending Orthopedic Surgeon and Orthopedic Director of the Women's Sports Medicine Center at HSS and a Professor in the Department of Orthopedic Surgery at Weill Cornell Medical College.

Dr. Hannafin was a USOC physician for the 2004 Olympic Games in Athens, Greece, and the 2003 Pan American Games in the Dominican Republic. She is currently the Head Team Physician for the WNBA New York Liberty and a Team Physician for the United States Rowing Team. She was an event physician at the 1996 Atlanta Olympic Games (rowing); and the New York City Marathon. Dr. Hannafin was a team physician for the WUSA New York Power from 2000-2003 and an Assistant Team Physician to the New York Mets from 1992-1996. She has been team physician to the U.S. Rowing Team since 1994 and is the Chair of the USRowing Sports Medicine Committee. She also serves as a member of the FISA Medical Commission and has served as a FISA Medical Officer at multiple World Championship and World Cup events in addition to the 2012 London Olympic Games. Dr. Hannafin was a member of the silver medalist lightweight double at the 1984 World Rowing Championships and a three-time gold medalist at the U.S. National Rowing Championships. She is currently the Vice President of the Board of Trustees of the National Rowing Foundation.

Dr. Hannafin was the first female president of the American Orthopaedic Society for Sports Medicine (2013-2014) and is also a past president of the Herodicus Society. In addition, she has served as vice president and secretary of the AOSSM board, chair of its committees on Enduring Education and Research, and as a member of numerous other AOSSM committees. She was a member of the Board of the Orthopaedic Research and Education Foundation from 2006-2012.

Publishing over 100 papers in peer-reviewed journals and writing over 20 book chapters, Dr. Hannafin is also the co-author of the book Say Goodbye to Knee Pain. Dr. Hannafin has been honored as one of The Best Doctors in America for the past twenty years and in 2013 she received the Castle-Connolly Physician of the Year Award. She was awarded the Hospital for Special Surgery Lifetime Achievement Award in 2014.

Dr. Hannafin was the first Clinician-Scientist at the Hospital for Special Surgery and maintained an active research program in the area of ligament physiology for over 20 years. She no longer maintains an independent research program but serves as a collaborator and mentor. Dr. Hannafin received NIH RO1 funding and foundation funding in support of this research. She has served as a full member of the SBSR NIH Study Section and as an ad hoc member of a number of other Study Sections. Dr. Hannafin serves as an reviewer for a variety of scientific journals including Journal of Shoulder and Elbow Surgery, Journal of Orthopaedic Research, American Journal of Sports Medicine, Journal of Bone and Joint Surgery, Journal of the American Academy of Orthopaedic Surgeons, Clinical Orthopaedics and Related Research and Sports Health.