Ernst Felix Hoppe-Seyler (born December 26, 1825, Freyburg an der Unstrut, Halle—died August 10, 1895, Wasserburg am Bodensee) was a German physician, known for his work toward establishing physiological chemistry (biochemistry) as an academic discipline. He was the first to obtain lecithin in a pure form and introduced the word proteid (now protein). Additional contributions included metabolic studies and researches on chlorophyll and on blood, especially hemoglobin, which he obtained in crystalline form.
Hoppe-Seyler founded (1877) and edited the first biochemical journal, Zeitschrift für Physiologische Chemie, and, apart from numerous scientific papers, published Physiologische Chemie, 4 vol. (1877–81), and Handbuch der Physiologisch- und Pathologisch-Chemischen Analyse (1858).