Trans-limonene oxide, also known simply as limonene oxide, is a cyclic ether and a chemical compound found in citrus fruits, particularly in the essential oils of lemon, lime, and orange. Its chemical structure consists of a six-membered ring with an oxygen atom, and it is classified as a terpene oxide. The "trans" designation indicates the relative orientation of substituents around the ring.

Limonene oxide, like other terpenes found in citrus oils, possesses antioxidant properties. Antioxidants help neutralize harmful free radicals in the body, potentially reducing oxidative stress and its associated health risks. In some industrial processes, limonene oxide may be used as a solvent or as an intermediate compound in the synthesis of other chemicals.

Limonene oxide, trans-