2024 Republican Party presidential primaries

Presidential primaries and caucuses are being held to select delegates to the 2024 Republican National Convention to determine the party's nominee for president in the 2024 United States presidential election. The Republican primaries and caucuses have taken place or will take place in all 50 U.S. states, the District of Columbia, and five U.S. territories between January and June 2024. The 2024 Republican National Convention is scheduled to be held in July at the Fiserv Forum in Milwaukee, Wisconsin.

In 2023, a crowded field of candidates emerged, including Florida governor Ron DeSantis, former Ambassador to the United Nations Nikki Haley, wealth management executive Vivek Ramaswamy, and former president Donald Trump. Trump has maintained a consistent lead in primary polling since 2020. Among non-Trump candidates, DeSantis initially polled in a close second behind Trump, but his polling numbers steadily declined throughout 2023. Ramaswamy experienced a polling surge in mid-2023, but this surge proved to be brief. Haley's campaign began picking up steam in the final months of 2023, though neither she nor any other candidate came close to Trump in polling. The Republican primaries were referred to as a "race for second" due to Trump's consistent lead in polls.

At the January 15 Iowa caucuses, Trump posted a landslide victory, with DeSantis narrowly beating out Haley for second place and Ramaswamy in a distant fourth. Following the Iowa caucuses, Ramaswamy and DeSantis dropped out of the race and endorsed Trump, leaving Trump and Haley as the only remaining major candidates. Trump then defeated Haley in the January 23 New Hampshire primary, albeit by a smaller margin of victory than he achieved in Iowa; he defeated Haley again in the February 24 South Carolina primary a month later. After Trump's overwhelming victories nationwide on Super Tuesday, Haley suspended her campaign on March 6, having only won Vermont and the District of Columbia.

Some Republicans have expressed concerns about Trump's candidacy due to his loss in 2020, his alleged role in inciting the January 6 United States Capitol attack, his ongoing criminal indictments, and the results of the 2022 midterms (in which several Trump-endorsed candidates lost key races). However, many others have supported him and decried the investigations as politically motivated. Trump maintains high favorability ratings among Republican voters. Trump's eligibility to appear on the ballot was challenged by some voters and political leaders in Colorado, Maine and Illinois, but these efforts were rejected by the Supreme Court of the United States in a unanimous decision. Trump became the presumptive nominee on March 12, with his victory in the Washington primary bringing him over the 1,215 delegate threshold needed to clinch the nomination.