Ognjen Gajić (born 1963), is a Bosnian–American intensive care physician, pulmonologist, university professor and a former musician. He serves as a Clinical Informaticist and a Critical Care Specialist of the Pulmonary Medicine Department at the Mayo Clinic in Rochester, Minnesota. and as a Professor of Medicine at the Mayo Clinic School of Medicine. He first found mainstream success as a member of the original lineup of a Bosnian rock band Zabranjeno Pušenje.