A native of Michigan, Dr. O’Neill received both his undergraduate and Ph.D. in physiology from Michigan State University and his medical degree from Virginia Commonwealth University. He then completed residencies in general surgery at the University of Virginia and in surgical critical care at Vanderbilt University Medical Center. He then concluded his clinical training as a trauma and emergency surgery fellow at Vanderbilt. Dr. O’Neill is a Clinical Assistant Professor of Surgery at the University of Arizona, College of Medicine – Phoenix Campus. At Maricopa Integrated Health System in Phoenix, Arizona, Dr. O’Neill is the Co-Director of the Surgical Intensive Care Unit, the Program Director of the Surgical Critical Care Residency, and the Medical Director of Trauma Research. He is an active clinician, researcher, and educator in the field of trauma, emergency general surgery, and surgical critical care.

Dr. O’Neill has been the local primary investigator on several sponsored grants. Working with Vanderbilt University, one project has assessed frequency of delirium in critically-ill burn patients. Another study with the University of Virginia is examining the appropriate length of time to give antibiotics for intraabdominal infections.

In addition to research, Dr. O’Neill provides lecture series to professionals including firefighters and first-responding personnel on topics such as abdominal trauma and trauma resuscitation. Dr. O’Neill is also an instructor for the Advanced Trauma Life Support Course (ATLS) and ATLS Instructor’s Course and is an ATLS Az State Faculty member.

Dr. O’Neill is currently the treasurer of the Arizona Trauma and Acute Care Consortium. Dr. O’Neill holds affiliations in multiple organizations, including Fellow of the American College of Surgeons (F.A.C.S), the Eastern Association for the Surgery of Trauma, American Trauma Society, American Medical Association, and the Surgical Infection Society. Dr. O’Neill has authored dozens of journal articles and is an active reviewer for Surgical Infections, the official journal for the Surgical Infection Society, devoted to the topic of surgically-induced or treated infections. He has been honored with awards such as the Jerry B Scott Award for Excellence in Teaching, Research, and Service at Michigan State University, the Young Investigator Award from the Shock Society, and the Arizona Legislature’s Physician for the Day.

Dr. O’Neill resides in Phoenix with his wife and two sons.