Timothy Francis Murphy is an American former politician and psychologist who served as the U.S. representative for Pennsylvania's 18th congressional district from 2003 until his resignation in 2017. The district included several suburbs south of Pittsburgh. A member of the Republican Party, he also represented the 37th Senate district in the Pennsylvania State Senate from 1996 to 2003. Murphy consistently carried the 18th district with at least 58% of the vote, including unopposed re-election bids in 2014 and 2016.

Pennsylvania's 18th congressional district was a district including the city of Pittsburgh and parts of surrounding suburbs. A variety of working class and majority black suburbs located to the east of the city were included, such as McKeesport and Wilkinsburg. Also a major part of the district was a number of middle class suburbs that have historic Democratic roots, such as Pleasant Hills and Penn Hills. The district became obsolete following the 2020 United States census. It was largely replaced by Pennsylvania's 12th congressional district.