USS Keosauqua was a proposed United States Navy screw sloop-of-war or steam frigate that was cancelled in 1866 without being completed. Keosauqua was a wooden-hulled bark-rigged (or ship-rigged) Contoocook-class screw sloop-of-war or steam frigate with a single funnel slated to be built for the Union Navy late in the American Civil War. She was listed in the 1864 Naval Register as "building;" her hull was projected but never completed.