John Blair Smith Todd (April 4, 1814 – January 5, 1872) was a Delegate from Dakota Territory to the United States House of Representatives and a general in the Union Army during the American Civil War.

Todd graduated from the United States Military Academy at West Point, New York, in 1837,[2] and was assigned to the 6th U.S. Infantry.

Todd was on garrison and frontier duty till 1855, when he was engaged in the action of Blue Water against the Sioux Indians.

He resigned from the United States Army on September 16, 1856, and became an Indian trader, settling at Fort Randall, Dakota Territory.

When the Dakota Territory was formed, Todd was elected as a Democrat to the House, serving from December 9, 1861, to March 3, 1863.