Catherine Louisa Pirkis was a British author of detective fiction. Throughout her career as a writer, Pirkis would sometimes write under the name of "C.L. Pirkis", to avoid gender association.

Cecil Torr was a British antiquarian and author.

Cesare Lombroso was an Italian eugenicist, criminologist, phrenologist, physician, and founder of the Italian school of criminology. Lombroso rejected the established classical school, which held that crime was a characteristic trait of human nature. Instead, using concepts drawn from physiognomy, degeneration theory, psychiatry, and Social Darwinism, Lombroso's theory of anthropological criminology essentially stated that criminality was inherited, and that someone "born criminal" could be identified by physical (congenital) defects, which confirmed a criminal as savage or atavistic.

Chapman Cohen was an English freethinker, atheist, and secularist writer and lecturer.

Charles Austin Beard was an American historian and professor, who wrote primarily during the first half of the 20th century. A history professor at Columbia University, Beard's influence is primarily due to his publications in the fields of history and political science. His works included a radical re-evaluation of the Founding Fathers of the United States, whom he believed to be more motivated by economics than by philosophical principles. Beard's most influential book, An Economic Interpretation of the Constitution of the United States (1913), has been the subject of great controversy ever since its publication. While it has been frequently criticized for its methodology and conclusions, it was responsible for a wide-ranging reinterpretation of early American history.

Charles Abram Ellwood was one of the leading American sociologists of the interwar period, studying intolerance, communication and revolutions and using many multidisciplinary methods. He argued that sociology should play a role in directing cultural evolution through education of society.

Reverend Charles Augustus Goodrich was an American author and Congregational minister, who popularized the motto "a place for everything and everything in its place". His uncle was Chauncey Goodrich; his siblings included a brother Samuel Griswold Goodrich, and a sister, Abigail Goodrich Whittlesey.

Charles Alan Fyffe (1845–1892) was an English historian, who was also well known as a journalist and a political candidate.

Charles Alden Seltzer was an American writer. He was a prolific author of western novels, had writing credits for more than a dozen film titles, and authored numerous stories published in magazines, most prominently in Argosy.

Charles Babbage was an English polymath. A mathematician, philosopher, inventor and mechanical engineer, Babbage originated the concept of a digital programmable computer.