It is becoming increasingly clear that the dominant, century-old neurocentric view of neurodegeneration is insufficient to explain why certain neurons degenerate, in particular with aging. Genetic studies in patient populations as well as mechanistic and functional studies in animal models altogether implicate nonneuronal cells, especially glia, to play more than bystander roles in neurodegeneration. Throughout the life span, neuronal function and homeostasis are modulated by glia, the functions of which become even more critical with aging. This review highlights key emerging concepts of the role of glia in neurodegeneration.