Frederick Townsend (September 21, 1825 – September 12, 1897) was a Union officer in the American Civil War. He founded and was Colonel of the 3rd New York Regiment, and later served with the US Army's 18th Infantry, where he was brevetted a brigadier general. Townsend served three terms as Adjutant General of the State of New York, from 1857–1861, and again in 1880.