Isham Nicholas Haynie (1824-1868) was a lawyer, politician, soldier and officer in the Union Army during the American Civil War.

He was colonel of the 48th Illinois Volunteer Infantry Regiment at the battles of Fort Donelson and Shiloh.

At a young age he moved to Illinois where he worked as a farmer before volunteering for service in the Mexican–American War.

[4] When Ulysses S. Grant organized his expedition to Fort Henry, Haynie became part of William H. L. Wallace's brigade in John A. McClernand's division.

Morrison was struck in the hip, taking him off the field and removing any command ambiguity between him and Haynie.

During the fighting on April 6 around Shiloh Church, Haynie was struck in the left thigh and forced to turn over command of the regiment.

Meanwhile, having recovered from his Shiloh wound, he was appointed to command of the 1st Brigade, 3rd Division, XVII Corps.