Raphael Mechoulam (born 1930) is an Israeli organic chemist and professor of Medicinal Chemistry at the Hebrew University of Jerusalem in Israel. Mechoulam is best known for his work (together with Y. Gaoni) in the isolation, structure elucidation and total synthesis of Δ⁹-tetrahydrocannabinol, the main active principle of cannabis and for the isolation and the identification of the endogenous cannabinoids anandamide from the brain and 2-arachidonoyl glycerol (2-AG) from peripheral organs together with his students, postdocs and collaborators.