David Jack Foster (November 2, 1859 – September 10, 1948) was a United States Army officer in the late 19th and early 20th centuries.

His father died when he was young, and after attending the local public schools, Foster went to Chicago in order get find better opportunities, with several members of his family following him shortly after.

On July 17, 1877, after making a living by selling insurance and working at the local post office, Foster enlisted in the Sixth Illinois Infantry.

On May 11, 1898, Foster and his regiment were mobilized into service because of the Spanish–American War, and they traveled to Cuba and Puerto Rico, where they remained until September 7 of that same year[1] before being mustered out on November 25.

[2] Foster was promoted to the rank of brigadier general of the Illinois National Guard on August 3, 1903, and he assumed command over the 32nd Infantry Brigade in Chicago.