The 2024 Maine Republican presidential primary was held on March 5, 2024, as part of the Republican Party primaries for the 2024 presidential election. 20 delegates to the 2024 Republican National Convention were allocated on a winner-take-most basis. The contest was held on Super Tuesday alongside primaries in 14 other states. This was a semi-closed primary where party members may only vote in their respective party's primary, but unenrolled voters may choose a party's primary to participate in. This change in law from Maine's previous closed primary went into effect on May 14, 2022, without Gov. Janet Mills' signature.

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.