Lipoprotein lipase (EC 3.1.1.34) is an enzyme which hydrolyzes lipids in lipoproteins, like those found in chylomicrons and very low density lipoproteins (VLDL), into three free fatty acids and one glycerol molecule. It requires Apo-CII as a cofactor. Lipoprotein lipase is specifically found in endothelial cells lining the capillaries.

Insulin is known to enhance LPL synthesis in adipocytes and its placement in the capillary endothelium. LPL has different isozymes in different tissues. The form that is in adipocytes is activated by insulin, whereas that in muscle and myocardium is not. This helps to explain why adipose cells gain fat in a well-fed state.A number sign is used with this entry because type I hyperlipoproteinemia can be caused by mutation in the lipoprotein lipase gene (LPL).