William Cary Sanger Sr. (May 21, 1853 – December 6, 1921) was an American politician who served as the United States Assistant Secretary of War from 1901 to 1903.

[1] He was born on May 21, 1853, in Brooklyn, New York City, to Henry Sanger (1823–1888) and Mary E. Requa (1835–1910).

He attended Brooklyn Polytechnic and then Harvard College, where he graduated with an A.B.

[1] He was the United States Assistant Secretary of War from 1901 to 1903.

[1] From 1911 to 1913 he served on the New York State Hospital Commission.