Astrocytes tile the entire CNS. They are vital for neural circuit function, but have traditionally been viewed as simple homogenous cells that serve the same essential supportive roles everywhere. Here, we summarize exciting breakthroughs that instead indicate astrocytes represent a population of complex and functionally diverse cells. Physiological diversity of astrocytes is apparent between different brain circuits and microcircuits, and individual astrocytes display diverse signaling within subcellular compartments. With respect to injury and disease, astrocytes undergo diverse phenotypic changes that may be protective or causative with regard to pathology in a context dependent manner. These new insights herald the concept that astrocytes represent a diverse population of genetically tractable cells that mediate neural circuit specific roles in health and disease.