Charles Tanford (December 29, 1921 – October 1, 2009) was a German-born protein biochemist. He died in York, England, on October 1, 2009.

Charles Tanford was born in Halle, Germany in 1921 to Majer and Charlotte Tannenbaum. His parents, who were Jewish, fled to England in 1929 anticipating the coming rule of the Nazi Party, and changed their name to Tanford. At the outbreak of war in Europe in 1939, Tanford was sent to New York to live with relatives. Despite Tanford's attempts to persuade them to leave, many of his relatives stayed behind in Germany and subsequently were murdered in the Holocaust. While in the United States, Tanford earned a B.A. in chemistry from New York University in 1943 and worked on the Manhattan Project in Oak Ridge.

In 1947, Tanford received his Ph.D. in Chemistry at Princeton University, working on combustion. He is credited with contributing to the "Tanford-Pease Theory of burning velocity". After graduating from Princeton, Tanford spent two years at Harvard University in the laboratory of E. J. Cohn and John Edsall, where he changed his research focus to protein biochemistry.

Tanford was hired as an assistant professor by the University of Iowa, where, in 1954, he was then promoted to associate professor and, again, in 1959, to full professor. In 1960, Tanford joined the faculty at Duke University as a professor of biochemistry. In 1970, he was named James B. Duke Professor of Biochemistry. He moved to the Department of Physiology in 1980, where his research efforts were concentrated on the movement of ions across cell membranes together with his collaborators Dr. E. A. Johnson and Dr. Jacqueline Reynolds.

In 1994 Tanford recalled, "I had been stimulated by Walter Kauzmann to move into protein chemistry and that made it logical that 'large molecules' should be my domain." His postdoctoral research was concerned with physical chemistry inspired by Kai Linderstrom-Lang. He wrote, "What I had been taught was the more elegant process of using equations: equations that linked thermodynamic properties, dielectric constant and dipole moment, binding equilibria, and a host of other possibilities to revealing molecular characteristics." His book on macromolecules, The Physical Chemistry of Macromolecules (1961) took ten years to write, and peer review "came only after submission of the final manuscript, and when it came it was a disaster. There were 2 reviewers and their criticism was scathing; I had got it all wrong, they said, and the book was declared effectively unpublishable...John Wiley & Sons reluctantly agreed to publish...the book was in fact a success..."

In 1973 Tanford published The Hydrophobic Effect, which covered proteins in all their various guises including those within cell membranes. Although he popularized the term hydrophobic effect, he attributed the origin of this concept to G. S. Hartley and the later efforts of Walter Kauzmann. Tanford gave great credit to the giants upon whose shoulders he stood.

Among other topics Tanford studied protein titration curves and protein denaturation, in both cases as applied to lysozyme. He also published important work on protein hydration and on the viscosity of solutions of proteins.

In 1981, Tanford became a founding member of the World Cultural Council.