红斑性狼疮（英语：systemic lupus erythematosus，缩写：SLE；又称全身性红斑狼疮或系统性红斑狼疮）是一种慢性的自身免疫疾病。和其他自身免疫疾病一样，免疫系统攻击自身细胞和组织，导致发炎和组织损害。红斑性狼疮可能影响各种器官，包括心脏、关节、皮肤、肺、血管、肝、肾脏，以及神经系统。SLE的自然病程多表现为病情的加重与缓解交替，通常无法预知何时发病。任何年龄的人都可能得到红斑性狼疮，但它通常发生于年轻女性，有90%的患者是女性。红斑性狼疮目前无法治愈，但它的症状是可以治疗的，以使用类固醇和免疫抑制剂为主。

Systemic lupus erythematosus, often abbreviated as SLE or lupus, is a systemic autoimmune disease (or autoimmune connective tissue disease) in which the body’s immune system mistakenly attacks healthy tissue. There are many kinds of lupus. The most common type is systemic lupus erythematosus (SLE), which affects many internal organs in the body. SLE most often harms the heart, joints, skin, lungs, blood vessels, liver, kidneys, and nervous system. The course of the disease is unpredictable, with periods of illness (called flare-ups) alternating with remissions.