Christian Boehmer Anfinsen, Jr. (March 26, 1916 - May 14, 1995) was a chemist and a 1972 Nobel Prize winner for work on ribonuclease, especially concerning the connection between the amino acid sequence and the biologically active conformation.

Anfinsen was born in Monessen, Pennsylvania. He earned a bachelor's degree from Swarthmore College in 1937, a master's degree in organic chemistry from the University of Pennsylvania in 1939, and a Ph.D. in 1939 from Harvard University.

In 1961 he showed that ribonuclease could be refolded after denaturation while preserving enzyme activity, thereby suggesting that all the information required by protein to adopt its final conformation is encoded in its primary structure.

He was a convert to Judaism by going through the gijur-process.