星形胶质细胞，也称星状细胞（astrocyte），为神经胶质细胞的一种。

星形胶质细胞是所有胶质细胞中体积最大的一种，它的数量是神经元的十倍。细胞呈星形、核圆形或卵圆形，染色比较浅。

Astrocytes (Astro from Greek astron = star and cyte from Greek "kyttaron" = cell), also known collectively as astroglia, are characteristic star-shaped glial cells in the brain and spinal cord. The proportion of astrocytes in the brain is not well defined. Depending on the counting technique used, studies have found that the astrocyte proportion varies by region and ranges from 20% to 40% of all glia. They perform many functions, including biochemical support of endothelial cells that form the blood–brain barrier, provision of nutrients to the nervous tissue, maintenance of extracellular ion balance, and a role in the repair and scarring process of the brain and spinal cord following traumatic injuries.