Henry Larcom Abbot (August 13, 1831 – October 1, 1927) was a military engineer and career officer in the United States Army. He served in the Union Army during the American Civil War and was appointed brevet brigadier general of volunteers for his contributions in engineering and artillery. In 1866 he received additional brevet appointments as major general of volunteers and brigadier general in the Regular Army. He conducted several scientific studies of the Mississippi River with Captain, later Major General Andrew A. Humphreys. After his retirement, Abbot served as a consultant for the locks on the Panama Canal. He was elected a Fellow of the American Academy of Arts and Sciences in 1863.