载脂蛋白A1（英语：Apolipoprotein A-I）为附著于高密度脂蛋白及乳靡小球上的载脂蛋白，基因编码为APOA1。可以活化卵磷脂-胆固醇酰基转移酶（Lecithin Cholesterol Acyltransferase）；当高密度脂蛋白运送组织中多余的胆固醇回到肝脏细胞中时，载脂蛋白A1同时也可作为高密度脂蛋白的配体，在脂质代谢中扮演重要角色。研究指出，APOA1的mRNA是由反义RNA转译出的内源性蛋白质所调控。

Apolipoprotein A-I is the major protein component of high density lipoprotein (HDL) in plasma. Chylomicrons secreted from the intestinal enterocyte also contain apo A-I, but it is quickly transferred to HDL in the bloodstream. The protein promotes fat efflux, including cholesterol, from tissues to the liver for excretion. It is a cofactor for lecithin cholesterolacyltransferase (LCAT) which is responsible for the formation of most plasma cholesteryl esters. Apo A-I was also isolated as a prostacyclin (PGI2) stabilizing factor, and thus may have an anticlotting effect. Defects in the gene encoding it are associated with HDL deficiencies, including Tangier disease, and with systemic non-neuropathic amyloidosis. ApoA1 is often used as a biomarker for prediction of cardiovascular diseases and the ratio apoB- 100/apoA1 has been reported as a stronger predictor for the risk of myocardial infarction than any other lipid measurement. ApoA1 is routinely measured using immunoassays such as ELISA or nephelometry.

Apolipoprotein A1 is a protein that in humans is encoded by the APOA1 gene. It has a specific role in lipid metabolism. The text in a recent report suggested that APOA1 mRNA is regulated by endogenously expressed antisense RNA.