Mike Pence served as the 48th vice president of the United States during the first presidency of Donald Trump from January 20, 2017, to January 20, 2021. Pence, a member of the Republican Party who previously served as the Governor of Indiana from 2013 to 2017, was selected as Trump's running mate and took office following their electoral college victory in the 2016 presidential election over Democratic nominees Hillary Clinton and Tim Kaine. The defining moment of Pence's vice presidency was his refusal to obey Trump's orders to overturn the 2020 United States presidential election during the January 6, 2021 United States Capitol attack.

Pence's vice presidency was not as influential in day-to-day governance as his three predecessors, Al Gore, Dick Cheney, and Joe Biden. During Pence's first two years in office, the Republican Party held their majorities in the House of Representatives under Speaker Paul Ryan and the Senate under Senate Majority Leader Mitch McConnell during the 115th U.S. Congress. During Pence's tenure as vice president, he chaired the National Space Council and the White House Coronavirus Task Force.

Trump and Pence lost the 2020 presidential election to Joe Biden and Kamala Harris. Trump refused to concede, made false or unproven allegations of election fraud, and filed numerous unsuccessful lawsuits in multiple states. As vice president in his capacity as the president of the Senate, Pence oversaw the certification of Biden and Harris as the winners of the election, despite Trump's urging to overturn the election results and the attack on the U.S. Capitol on January 6, 2021. Trump and Pence were succeeded in office by Biden and Harris on January 20, 2021.

Pence distanced himself from Trump during and after January 6, 2021, endorsing candidates in primary elections in opposition to those supported by Trump and criticizing Trump's conduct on the day of the Capitol attack. In June 2023, Pence launched a 2024 presidential bid but withdrew by October. He declined to endorse Trump in 2024.

Shortly before the 2016 Indiana Republican presidential primary, Pence endorsed Texas U.S. Senator Ted Cruz, who would lose the primary to Trump. Pence then endorsed Trump after the latter became the party's presumptive nominee for president of the United States.

Donald Trump considered naming Pence as his vice presidential running mate along with other finalists including New Jersey governor Chris Christie and former House speaker Newt Gingrich. Pence had stronger connections at the time to the politically influential big donors, the Kochs, than Trump did. It was widely reported on July 14 that Pence planned to end his (Indiana gubernatorial) re-election campaign and accept the Republican vice presidential nomination instead. The following day, Trump officially announced on Twitter that Pence would be his running mate.

Immediately after the announcement, Pence said he was "very supportive of Donald Trump's call to temporarily suspend immigration from countries where terrorist influence and impact represents a threat to the United States". Pence said he was "absolutely" in sync with Trump's Mexican wall proposal, saying Mexico was "absolutely" going to pay for it.

According to a FiveThirtyEight rating of candidates' ideology, Pence was the most conservative vice-presidential candidate in the last 40 years.