Charles Baron Clarke (17 June 1832 – 25 August 1906) was a British botanist. He worked in as a civil servant in British India in the Bengal education department. He was also keenly interested in botany and held the position of superintendent of the Calcutta Botanical Gardens from 1869 to 1871. During this period he became a specialist on the Cyperaceae and based on their distributions developed an influential phytogeographical classification of British India.