Alexander Ahab Arnold (October 20, 1833 – March 1, 1915) was an American lawyer, livestock breeder, and Republican politician from Galesville, Wisconsin.

[4] Shortly after the death of his first wife and child, Arnold volunteered for service in the Union Army in the American Civil War.

[3] He was enrolled as captain of Company C in the 30th Wisconsin Infantry Regiment and mustered into service in August 1862.

[5] In the Dakota Territory, they assisted in establishing Fort Rice under the direction of General Alfred Sully.

[5] The Wisconsin companies left Fort Rice in October 1864 and proceeded to Louisville, Kentucky, arriving on November 29.

They were then organized into the 2nd brigade, 2nd division, Military District of Kentucky, and were assigned to guard a prison in Louisville.

Colonel Bartlett was assigned to a court martial detail, Major John Clowney was provost marshal at Frankfort.

[6] On his return from the war, Arnold decided to engage in agricultural pursuits, rather than continuing in the legal profession.

On the question of slavery, he endorsed the position of Stephen A. Douglas and supported his presidential campaign in 1860.