Elias Willard Smith (1814/1816–1886) was an American architect and civil engineer. He was born in 1814 or 1816 (sources differ) in Albany, New York, and died in 1886 in Washington, DC. He was educated as an engineer, at the Rensselaer Polytechnic Institute. As a graduation present from his father, he undertook a trip from St. Louis to the Rocky Mountains and back (1839–1840). During this trip, he recorded his observations in a journal, which was handed down in his family and later published in various scholarly venues.