Jerrold Meinwald (January 16, 1927 – April 23, 2018) was an American chemist known for his work on chemical ecology, a field he co-founded with his colleague and friend Thomas Eisner.

His interest in chemistry was sparked by fireworks done with his friend Michael Cava when they were still in junior high school.

Meinwald was also a music aficionado and studied flute with Marcel Moyse – the world's greatest flutist of his time.

A species on which he and Eisner published several times over decades is the moth Utetheisa ornatrix, which collects pyrrolizidine alkaloids from its food source[2] and uses them as a deterrent to predators; the male also uses them as a pheromone[3] and passes them on in its semen to the female who uses them to make her eggs unpalatable.

[2][4][5] In analysing the constituents of plant signalling, he developed a number of retrosynthetic techniques, including the Meinwald Rearrangement where an epoxide is converted to a carbonyl in the presence of a Lewis acid; he has also performed substantial research over forty years in NMR spectroscopy.