Nelson H. Henry (27 April 1855 – 16 March 1923) was an American medical doctor, politician, and military officer from New York.

[4][5] In March 1883, Henry joined the New York National Guard, receiving a first lieutenant's commission as assistant surgeon of the 12th Infantry Regiment.

[6] Henry returned to military service in March 1897, assigned as surgeon of the New York National Guard with the rank of colonel.

[6] In July 1898, Henry requested active duty for the Spanish–American War, and was commissioned as a major of United States Volunteers.

[6] He was assigned as surgeon of Second Division, Fourth Army Corps, and served at training camps in Tampa, Florida and Huntsville, Alabama until receiving his discharge in September.

[6] In December 1900, he was again appointed surgeon of the New York National Guard with the rank of colonel, to date from March 1897.

[6] He served until resigning on 31 May 1910; In February 1910, he received promotion to major general by brevet from Governor Charles Evans Hughes.

[7][8] Henry resigned as adjutant general in order to accept appointment as US Surveyor of the Port of New York, succeeding James S.