Dr. Deanna O'Neil joined South Bend Children's Dentistry, P.C. in 2008, she took over the practice in 2012. Dr. O'Neil is a native of La Crosse, Wisconsin. She graduated from Marquette University with a degree in Biology, then went on to earn her Doctor of Dental Surgery (DDS) degree from Marquette. She completed her Pediatric Dental Residency at Temple University Health Complex.

Dr. O'Neil is a member of the Mishawaka Dental Society, Indiana Dental Association, American Dental Association and The American Academy of Pediatric Dentistry. She is a Board Certified Pediatric Dentist and is a Diplomate of the American Board of Pediatric Dentistry. Dr. O'Neil has hospital privileges at Memorial Hospital of South Bend and St. Joseph Regional Medical Center. She is currently Vice-Chair of the Dental Department at Memorial Hospital and is on the Cleft Palate Clinic.