Christian Boehmer Anfinsen, Jr. (March 26, 1916–May 14, 1995) was an American biochemist. He shared the 1972 Nobel Prize in Chemistry with Stanford Moore and William Howard Stein for work on ribonuclease, especially concerning the connection between the amino acid sequence and the biologically active conformation.

In 1939, The American-Scandinavian Foundation awarded Anfinsen a fellowship to develop new methods for analyzing the chemical structure of complex proteins, namely enzymes, at the Carlsberg Laboratory in Copenhagen, Denmark.
In 1941, Anfinsen was offered a university fellowship for doctoral study in the Department of Biological Chemistry at Harvard Medical School. Anfinsen received his Ph.D. in biochemistry in 1943 from Harvard Medical School.
In 1950, the National Heart Institute, part of the National Institutes of Health in Bethesda, Maryland, recruited Anfinsen as chief of its Laboratory of Cell physiology.
In 1962, Anfinsen returned to Harvard Medical School as a visiting professor and was invited to become chair of the Department of Chemistry.
From 1982 until his death in 1995, Anfinsen was Professor of Biophysical Chemistry at Johns Hopkins.