The 2018 United States Senate election in Pennsylvania took place on November 6, 2018, to elect a member of the United States Senate to represent the State of Pennsylvania, concurrently with other elections to the United States Senate, elections to the United States House of Representatives, and various state and local elections. The primary elections were held on May 15. Incumbent Democratic Senator Bob Casey Jr. ran for re-election to a third term. Casey, who faced no primary opposition, defeated the Republican nominee, Lou Barletta, Green Party nominee Neal Gale, and Libertarian Party nominee Dale Kerns. Casey was the first senator to be elected to a third term from Pennsylvania since Arlen Specter in 1992, and the first Pennsylvania Democrat to be popularly elected to three terms in the Senate.

Richard Saccone is an American educator and far-right politician who represented Pennsylvania's 39th district in the Pennsylvania House of Representatives from 2011 to 2019. A Republican, he was his party's nominee for the March 2018 special election to fill in the vacant U.S. House seat for the 18th congressional district. Saccone lost to Democratic candidate Conor Lamb by a margin of 0.3%.