Richard John Santorum Sr. (born May 10, 1958) is an American politician, attorney, author, and political commentator who represented Pennsylvania in the United States Senate from 1995 to 2007. He was the Senate's third-ranking Republican during the final six years of his tenure. He also ran unsuccessfully for President of the United States in the 2012 Republican primaries, finishing second to Mitt Romney.

Santorum was elected to the United States Senate from Pennsylvania in 1994. He served two terms until losing his 2006 reelection bid. A Roman Catholic, Santorum is a social conservative who opposes abortion and same-sex marriage and embraced a cultural warrior image during his Senate tenure. While serving as a senator, Santorum authored the Santorum Amendment, which would have promoted the teaching of intelligent design. He was a leading sponsor of the 2003 federal law known as the Partial-Birth Abortion Ban Act.

In the years following his departure from the Senate, Santorum has worked as a consultant, private practice lawyer, and news contributor. He ran for the Republican nomination in the 2012 U.S. presidential election. Before suspending his campaign on April 10, 2012, Santorum exceeded expectations by winning 11 primaries and caucuses and receiving nearly four million votes, making him the runner-up to eventual nominee Mitt Romney. Santorum ran for president again in 2016, but ended his campaign in February 2016 after a poor showing in the Iowa caucuses. In January 2017, he became a CNN senior political commentator. However, he was terminated from his contract with CNN in May 2021 due to comments he made about Native Americans a few weeks prior which were deemed "dismissive".