Barbara N. Horowitz, M.D., (also known as Barbara Natterson-Horowitz) is a cardiologist, academic and author. She is a Professor of Medicine in the Division of Cardiology at University of California, Los Angeles (UCLA) and a Visiting Professor in the Department of Human Evolutionary Biology at Harvard University and has been on the faculty of Harvard Medical School since 2020. Horowitz is a New York Times bestselling author of the book Zoobiquity (co-authored with Kathryn Bowers) on the subject of a cross-species approach to medicine which includes veterinary and evolutionary perspectives. In 2019, Horowitz and Bowers co-authored their second book, Wildhood.