棘红细胞（英语：Acanthocyte、spur cell，字源来自希腊文acantha，意为「刺」）是细胞膜有针状突起的异常红血球。棘红细胞外表粗糙而不规则，且具有许多星状的圆锯齿突起。可在无β脂蛋白血症、肝病、棘红细胞增多症、麦克劳德综合征、甲状腺机能低下症、神经性厌食症、神经性棘红细胞增多症、婴儿固缩细胞增多症、特发性新生儿肝炎、充血性脾脏肿大（congestive splenomegaly）、齐福氏综合征与慢性肉芽肿病等神经、血液疾病患者的血液抹片中发现。

Acanthocyte (from the Greek word ἄκανθα acantha, meaning 'thorn'), in biology and medicine, refers to a form of red blood cell that has a spiked cell membrane, due to abnormal thorny projections. A similar term is spur cells. Often they may be confused with echinocytes or schistocytes.