Mary-Frances O'Connor is an American psychologist and an associate professor of psychology at the University of Arizona. She directs the Grief, Loss, and Social Stress (GLASS) Lab. Her research investigates the effects of grief on the brain and the body. O'Connor earned a doctorate from the University of Arizona in 2004 and completed a fellowship at UCLA. After a faculty appointment at UCLA Cousins Center for Psychoneuroimmunology, she returned to the University of Arizona in 2012.

Her work has been published in the American Journal of Psychiatry, Biological Psychiatry, and Psychological Science, and has been featured in Newsweek, New York Times, and Washington Post. Having grown up in Montana, she now resides in Tucson, Arizona.