William Benjamin Carpenter was born on October 29, 1813, in Exeter, Devon, England, the eldest son of Dr. Lant Carpenter (1780-1840), an English educator and Unitarian minister. He was a brother of the social reformer Mary Carpenter (1807-1877).

He was an English physician, invertebrate zoologist, and physiologist. He attended lectures at Bristol Medical School and later studied at University College London (1834–1835). He received his MD from the University of Edinburgh in 1839. In 1871, he received an LL.D. also from the University of Edinburgh. His work in comparative neurology was recognized in 1844 by his election as a Fellow of the Royal Society. His appointment as Fullerian Professor of Physiology at the Royal Institution in 1845 enabled him to exhibit his powers as a teacher and lecturer. He worked hard as an investigator, author, editor, demonstrator, and lecturer throughout his life; but it was his researches in marine zoology, notably in the lower organisms, as Foraminifera and Crinoids, that were the most valuable. In 1868, he participated in the oceanographic survey with HMS Lightning and later the more famous Challenger Expedition. He was president of the Quekett Microscopical Club from 1883 to 1885 and was awarded the Royal Medal in 1861. His most famous work “The Use and Abuse of Alcoholic Liquors in Health and Disease” (1850) became one of the first temperance books to promote the fact that alcoholism is a disease. In 1856, he became Registrar of the University of London, the office he held for twenty-three years. He supported the education of women by teaching at the newly founded Bedford College, London (1849-1850). Carpenter identified as a rationalist and a Unitarian, criticizing the claims of paranormal phenomena, psychical research, and spiritualism.

In 1840, he married Louisa Ann Powell (1812–1887). He died on November 19, 1885, in London, England.