John Giles Adams (December 2, 1792 – May 14, 1832) was a cavalry officer in the Illinois Militia during the Black Hawk War of 1832. He was born in Nashville, Tennessee and came to Illinois in 1828, eventually marrying and fathering eight children. Adams served as captain in a militia company of more than 50 mounted volunteers who were mustered into service on April 17, 1832 following the onset of the war. Adams' company saw action in the disastrous militia defeat at Stillman's Run on May 14. Adams and several members of his company were killed while making a stand upon a hillside near the main militia camp.