Bloch was born in Neisse (Nysa) in the German Empire's Prussian Province of Silesia. He was the second child of a middle class family. From 1930 to 1934, he studied chemistry at the Technical University of Munich. In 1934, due to the Nazi persecutions of Jews, he fled to the Schweizerische Forschungsinstitut in Davos, Switzerland, before moving to the United States in 1936. Later he was appointed to the department of biological chemistry at Yale Medical School.

In the United States, Bloch enrolled at Columbia University, and received a Ph.D in biochemistry in 1938. He taught at Columbia from 1939 to 1946. From there he went to the university of Chicago and then to Harvard University as Higgins Professor of Biochemistry in 1954, a post he held until his retirement in 1982.

Bloch shared the Nobel Prize in Medicine or Physiology in 1964 with Feodor Lynen, for their discoveries concerning the mechanism and regulation of the cholesterol and fatty acid metabolism. He became a Fellow of the Royal Society in 1985.

Bloch died in Lexington, Massachusetts, of congestive heart failure, aged 88.