Horatio Allen (May 10, 1802 – December 31, 1889) was an American civil engineer and inventor, and President of Erie Railroad in the year 1843–1844.

[1] Born in Schenectady, New York, he graduated from Columbia University in 1823, and was appointed Assistant Engineer of the Delaware and Hudson Canal Company (precursor to the railroad).

He was therefore asked to arrange for the construction of 3 locomotives for the Canal Company's projected railway (as per his June 25, 1880 letter to the editor of the New York Times).

In 1829 he operated the first steam locomotive, one of the ones he ordered for the D&H, to run in America, the Stourbridge Lion, which ran successfully at Honesdale, Pennsylvania on August 8, 1829.

From 1829 to 1834 he was the chief engineer of the South Carolina Canal and Rail Road Company, at that time the longest railway in the world (about 136 miles/218 km).