1-Octen-3-ol, octenol for short and also known as mushroom alcohol, is a chemical that attracts biting insects such as mosquitoes. It is contained in human breath and sweat, and it was once believed that insect repellent DEET works by blocking the insects' octenol odorant receptors. 1-Octen-3-ol is a secondary alcohol derived from 1-octene. It exists in the form of two enantiomers, (R)-(–)-1-octen-3-ol and (S)-(+)-1-octen-3-ol.

Octenol is produced by several plants and fungi, including edible mushrooms and Lemon balm. Octenol is formed during oxidative breakdown of linoleic acid. It is also a wine fault, defined as a cork taint, occurring in wines made with bunch rot contaminated grape.

Octenol is used, sometimes in combination with carbon dioxide, to attract insects in order to kill them with certain electronic devices. Its odor has been described as green and moldy or meaty; it is used in certain perfumes.