Douglas Earl Applegate (born March 27, 1928) is a former American politician who represented the state of Ohio in the United States House of Representatives. A member of the Democratic Party, he served as the U.S. Representative for Ohio’s 18th Congressional District. His tenure in Congress began on January 4, 1977, and concluded on January 3, 1995, marking an 18-year career at the federal legislative level.

During his time in the House, Applegate served nine consecutive terms, reflecting sustained support from his constituents in Ohio’s 18th District. As a Democratic representative, he participated in the legislative process through committee work and floor votes, contributing to the shaping of national policy over nearly two decades. His service places him among the historical members of Congress who represented Ohio in the late twentieth century.