Ralph Isaacs Ingersoll (8 February 1789-26 August 1872) was a member of the US House of Representatives (NR-CN AL) from 4 March 1825 to 3 March 1833, interrupting Samuel A. Foot's terms. Born in New Haven, he practiced law before serving in the state house from 1820 to 1825, in Congress, and Minister to the Russian Empire from 1846 to 1848.