John Montgomery Crebs (April 9, 1830 – June 26, 1890) was a U.S. Representative from Illinois, as well as an officer and brigade commander in the Union Army during the American Civil War.

Born in Middleburg, Virginia, Crebs moved to Illinois in 1837 with his parents, who settled in White County.

Following the outbreak of the Civil War, Crebs was commissioned as the lieutenant colonel of the 87th Illinois Infantry in 1862.

After the close of the war, Crebs resigned his commission and returned to White County, where he resumed the practice of law.

This article incorporates public domain material from the Biographical Directory of the United States Congress