Douglas Hancock Cooper Johnston (October 13, 1856 – June 28, 1939), also known as "Douglas Henry Johnston", was a Chickasaw tribal leader who served as governor of the Chickasaw Nation from 1898 to 1902 and 1904 to 1939. In office, he was notable for ratifying the Atoka Agreement and defending the tribe against claims for more money. Prior to his election as governor, he was the superintendent of the Bloomfield Academy. From 1902 to 1904, he served in the Chickasaw Senate. President Theodore Roosevelt reappointed him as Governor of the Chickasaws after the Dawes Act terminated trial governments in Indian Territory.