He was born in Munich, the son of a physician and Professor Extraordinary of Forensic Medicine. In 1884, he began studies in chemistry with Adolf von Baeyer and in botany with Professor C. von Naegeli, at the Botanic Institute in Munich. After a period working with Otto Fischer in Erlangen, he was awarded a doctorate from the University of Munich in 1888.
Buchner married Lotte Stahl in 1900.
Buchner was awarded the 1907 Nobel Prize in Chemistry for his biochemical investigations and his discovery of non-cellular fermentation.
During World War I, Buchner served as a Major in a front-line field hospital at Folkschani, Romania. He was wounded on August 3, 1917 and died of these wounds nine days later in Munich.