Apolipoproteiner, proteindelen av lipoproteiner. Lipoproteinet low density lipoprotein (LDL) inneholder apolipoprotein B-100, mens very low density lipoprotein (VLDL) inneholder flere apolipoproteiner (B-100, E, C). High density lipoprotein (HDL) inneholder apolipoprotein A (ulike former).