Pierre-Joseph Pelletier (UK: , US: , French: [pj???oz?f p?ltje]; 22 March 1788 – 19 July 1842) was a French chemist and pharmacist who did notable research on vegetable alkaloids, and was the co-discoverer with Joseph Bienaimé Caventou of quinine, caffeine, and strychnine.
He was also a collaborator and co-author with Polish chemist Filip Walter.