The 1988 United States Senate election in Pennsylvania was held on November 8, 1988. Incumbent Republican U.S. Senator H. John Heinz III successfully sought re-election to another term, defeating Democratic nominee Joe Vignola.
Joe Vignola was not expected by Democratic Party leaders to have a substantial chance at defeating the popular incumbent John Heinz, even predicting that Vignola would become "Heinz's 58th variety," referring to an advertising slogan of the H. J. Heinz Company. Heinz, knowing this, ran a low-profile re-election campaign and was safely ahead in polling. Vignola traveled across Pennsylvania promoting an increase in domestic spending, including education and healthcare, while decreasing the defense budget to compensate. Vignola ran a positive campaign, in contrast with Cyril Wecht six years previously, although many Democratic ward leaders and committee members had given up on the campaign and had stopped campaigning for Vignola.
Heinz easily defeated Vignola to win the election and another term in the Senate, carrying every Pennsylvania county except Philadelphia, Vignola's home town, and by a comfortable 1.49 million vote margin. Heinz performed well in suburban areas, as well as the central, southwestern and northeastern portions of the state. Outside of Philadelphia, Vignola's best county-wide showing was in Mercer County, where he won 36% of the vote, and his poorest county-wide performance was in Snyder County, where he won 12% of the vote. Although Heinz's landslide victory was largely expected among Democratic leaders, Heinz won by a wide margin despite the Democrats' 551,000-voter registration advantage statewide.