The Freedom Caucus, also known as the House Freedom Caucus, is a congressional caucus consisting of Republican members of the United States House of Representatives. It is generally considered to be the most conservative bloc within the chamber. The caucus was formed in January 2015 by a group of conservatives and Tea Party movement members, with the aim of pushing the Republican leadership to the right. Its first chairman, Jim Jordan, described the caucus as a "smaller, more cohesive, more agile and more active" group of conservative representatives. Its current chairman, Andy Harris, is considered by some media to be a far-right politician due to some of his radical proposals.

The caucus is positioned right-wing to far-right on the political spectrum, and it is substantially linked to the values of national conservatism. The hardline conservative group favors social conservatism and small government, along with right-wing populist beliefs such as opposition to immigration reform. The group sought dozens of times to repeal the Affordable Care Act. Established as a more conservative alternative to the Republican Study Committee, the group initially emphasized fiscal conservatism and concerns about House rules, favoring budget cuts and a decentralization of power within the House of Representatives.

Known for their strategy of obstructionism and for defending false stories like the Planned Parenthood 2015 undercover videos controversy, according to Samuel L. Popkin, after the election of Donald Trump, the Freedom Caucus became what Politico described as "more populist and nationalist, but less bound by policy principles." The caucus has included some members who are libertarians. The caucus supports House candidates through its PAC, the House Freedom Fund. According to the January 6th Committee, members of the Freedom Caucus were instrumental in helping Donald Trump in his failed attempts to overturn the results of the 2020 United States presidential election.

The caucus originated during the mid–January 2015 Republican congressional retreat in Hershey, Pennsylvania. Nine conservative Republican members of the House began planning a new congressional caucus separate from the Republican Study Committee and apart from the House Republican Conference. The founding members who constituted the first board of directors for the new caucus were Republican representatives Scott Garrett of New Jersey, Jim Jordan of Ohio, John Fleming of Louisiana, Matt Salmon of Arizona, Justin Amash of Michigan, Raúl Labrador of Idaho, Mulvaney of South Carolina, Ron DeSantis of Florida and Mark Meadows of North Carolina.

At the retreat in Pennsylvania, the group settled on the name Freedom Caucus. Mick Mulvaney told Ryan Lizza of the New Yorker, "We had twenty names, and all of them were terrible. None of us liked the Freedom Caucus, either, but it was so generic and so universally awful that we had no reason to be against it." According to Lizza, "one of the working titles for the group was the Reasonable Nutjob Caucus."

During the crisis over the funding of the Department of Homeland Security in early 2015, the caucus offered four plans for resolution, but all were rejected by the Republican leadership. One of the caucus leaders, Raúl Labrador, said the caucus would offer an alternative that the most conservative Republican members could support.^{[needs update]}

The newly formed group declared that a criterion for new members in the group would be opposition to John Boehner as Speaker of the House and willingness to vote against or thwart him on legislation that the group opposed.

The House Freedom Caucus was involved in the resignation of Boehner on September 25, 2015, and the ensuing leadership battle for the new speaker. Members of the caucus who had voted against Boehner for speaker felt unfairly punished, accusing him of cutting them off from positions in the Republican Study Committee and depriving them of key committee assignments. Boehner found it increasingly difficult to manage House Republicans with the fierce opposition of conservative members of the Republican Party in the House, and he sparred with those House Republicans in 2013 over their willingness to shut down the government in pursuit of goals such as repealing the Affordable Care Act. These Republicans later created and became members of the Freedom Caucus in 2015.