2016 United States presidential election in Ohio

The 2016 United States presidential election in Ohio was held on Tuesday, November 8, 2016, as part of the 2016 United States presidential election in which all 50 states plus the District of Columbia participated. Ohio voters chose electors to represent them in the Electoral College via a popular vote, pitting the Republican Party's nominee, businessman Donald Trump, and running mate Indiana Governor Mike Pence against Democratic Party nominee, former Secretary of State Hillary Clinton, and her running mate Virginia Senator Tim Kaine. Ohio had 18 electoral votes in the Electoral College.

The 2016 election marked a turning point for Ohio, which had long been a swing state but was won by Trump by a margin of 8.07 points. Prior to the election, most news organizations considered Ohio as a close state leaning Republican, due to Trump's appeal to blue-collar voters in the Rust Belt. However, on election day Trump significantly overperformed expectations, with Clinton winning just 8 counties to Trump's 80. Ohio kept its streak of voting for the winner as a bellwether state since 1964, as it voted for Trump, who won nationally. Having previously voted Democratic in 2012 and 2008, the winning margin was the second largest of the states Trump flipped red, after Iowa.

This also marked the largest margin of victory since George H. W. Bush defeated Michael Dukakis in the state in 1988. In 2024, Trump surpassed Bush's 1988 margin, winning the state by double digits while running with Ohio native JD Vance. As of the 2024 presidential election, this is the last time Mahoning and Lorain counties voted for the Democratic candidate and the last time Montgomery voted for the Republican candidate.