Joseph Caventou was a French chemist who collaborated in 1817 with Pierre Joseph Pelletier (1788–1842) to isolate and name chlorophyll (choosing the Greek words for "green leaf"). They are considered the founders of alkaloid chemistry, having isolated veratrine, strychnine, brucine, quinine, and cinchonine. Caventou also extracted caffeine from coffee beans in 1822.

The son of an apothecary, Caventou studied in Paris where he was professor of toxicology (1835–1860) at the École de Pharmacie. He and Pelletier concentrated on research into plant chemistry in order to find the component that renewed air. They discovered that chlorophyll was the compound that turned plants green, and it was later shown that the molecules absorbed the Sun's light energy for photosynthesis.