Harmar Denny (13 May 1794-29 January 1852) was a member of the US House of Representatives (AM-PA 16) from 4 March 1829 to 3 March 1833 (succeeding William Wilkins and preceding Joseph B. Anthony) and from PA-22 from 4 March 1833 to 3 March 1837 (preceding Richard Biddle). Born in Pittsburgh, he practiced law before serving in the state house from 1824 to 1829, in Congress, as a Whig presidential elector in 1840, and later as a railroad president.