Alexander Jack, CB (19 October 1805 – 27 June 1857) was a Scottish officer in the service of the East India Company in the Bengal Army.

[1] Jack was present with his battalion at the Battle of Aliwal (medal), and acted as brigadier of the force sent against the town and fort of Kangra in the Punjab, when he received great credit for his extraordinary exertions in bringing up his 18-pounder guns, which he had been recommended to leave behind.

He became colonel on 20 June 1854, and on 18 July 1856 was appointed brigadier at Cawnpore, the headquarters of Sir Hugh Wheeler's division of the Bengal Army.

Wheeler maintained his position in an entrenched camp until 27 June, when an attempted evacuation was made in accordance with an arrangement entered into with Nana Sahib.

During the previous defence of the lines a brother, Andrew William Thomas Jack, who was on a visit from Australia, had his leg shattered, and succumbed under amputation.