ò-Eleostearic acid, or (9E,11E,13E)-octadeca-9,11,13-trienoic acid, is an organic compound with formula or H<sub>3</sub>C(CH<sub>2</sub>)<sub>3</sub>(CH=CH)<sub>3</sub>(CH<sub>2</sub>)<sub>7</sub>COOH. It is an all-trans isomer of octadecatrienoic acid.