Stress fractures result from skeletal failure resulting from submaximal repetitive forces over time. Sacral stress fractures may represent an underdiagnosed cause of low back and buttock pain. They occur primarily in two populations, young active persons and elderly osteoporotic women, usually corresponding to fatigue and insufficiency-type fractures, respectively. The clinical presentation of these fractures is similar, but the medical and rehabilitation management of these patient populations differs and is tailored to the specific underlying etiology. In both types of fractures, appropriate conservative measures generally result in good functional outcomes. This paper provides an overview of the anatomical considerations, risk factors, clinical presentations, diagnostic imaging findings, appropriate laboratory studies, medical management, and rehabilitation management of patients with sacral stress fractures.