Jonathan Knight (November 22, 1787 – November 22, 1858) was an American politician who served as an Opposition Party member of the U.S. House of Representatives for Pennsylvania's 20th congressional district from 1855 to 1857. He also served as a member of the Pennsylvania Senate for the 20th district from 1822 to 1828. He was a civil engineer who worked on the National Road and as the first chief engineer of B&O Railroad.