American chemist who, along with Jean-Marie Lehn (Lehn, Jean-Marie) and Donald J. Cram (Cram, Donald J.), was awarded the 1987 Nobel Prize for Chemistry for his synthesis of the crown ethers—a group of organic compounds that would selectively react with other atoms and molecules much as do the molecules in living organisms.

Born to a Norwegian father and a Korean mother, Pedersen went in the early 1920s to the United States to study chemical engineering at the University of Dayton in Ohio, where he took his bachelor's degree. He received a master's degree in organic chemistry at the Massachusetts Institute of Technology and in 1927 went to work for E.I. du Pont de Nemours & Co. as a research chemist. He worked there for the next 42 years.

In the 1960s Pedersen synthesized a group of compounds that he named crown ethers for their structure—a loose, flexible ring of carbon atoms punctuated at regular intervals with oxygen atoms. By varying the size of the rings, he found that crown ethers would bind the ions of certain metal elements at the centre of the “crown.” His discoveries were expanded upon by Lehn and Cram, and the result was the laboratory synthesis of molecules that could selectively react with other molecules in much the same way that enzymes and other natural biological molecules do.