William Beatty Archer (January 30, 1793 – August 9, 1870) was an Illinois politician and businessman. Archer was a member of the Illinois General Assembly from 1825 until 1843, during which time he also served on the state Board of Canal Commissioners and unsuccessfully ran for higher office twice. He also founded the city of Marshall, Illinois, was a captain in the Black Hawk War, and supported Abraham Lincoln's vice presidential nomination at the first Republican National Convention in 1856.