gamma-Valerolactone is an organic compound with the formula C₅H₈O₂. This clear liquid is one of the more common lactones. It is a structural isomer of delta-valerolactone. Because of its herbal odor, it is used in the perfume and flavor industries.

gamma-Valerolactone (GVL) is a promising "green" liquid fuel. While the combustion of GVL yields only half the energy that is produced in the combustion of octane, GVL can be processed further into longer hydrocarbon chains that could be used as components in automobile gasoline mixtures.

A current method to produce gamma-valerolactone designed by James Dumesic, a chemical engineer from the University of Wisconsin–Madison, is to first apply weak sulfuric acid to the cellulose found in biomasses, such as corn stover, sawgrass, or wood, to break it down into glucose and other sugars. Cellulase enzymes can help this process, but are not necessary due to the cost of these enzymes The sugars can then be processed with harsh sulfuric acid to yield levulinic acid and formic acid. The levulinic acid can then be cyclized and the product hydrogenated (according to Dumesic, this can be achieved by mixing levulinic acid with a ruthenium-rhenium catalyst) to give gamma-valerolactone, which has potential applications as a liquid fuel.