Isaiah Stillman (c. 1793–15 April 1861) was an American Cavalry Major who led the Illinois militia in the first armed confrontation of the Black Hawk War against Black Hawk's Sauk Indian Band.

Isaiah Stillman was born and raised in the state of Massachusetts, but he left the east and traveled to Illinois to become a trader of pots, pans, and other items.

[1] For a time, he lived in Coopers Creek Landing in Fulton County, before deciding to join the Illinois militia as a captain at the age of 35 in 1827.

[1] By the early part of 1832, Isaiah had attained the rank of Brigadier General-elect.

[1] He was unable to recruit a full battalion, so he was made a major rather than a general.