The LXIV Legislature of the Mexican Congress was the meeting of the Mexican Congress of the Union that convened on 1 September 2018 and ended on 31 August 2021. It is composed of the 500 federal deputies and 128 senators elected in the 2018 Mexican general election. While the deputies served only in the LXIV Legislature, the senators, elected to six-year terms, also formed the Senate in the LXV Legislature, which convened in 2021.

The Congress of the Union, formally known as the General Congress of the United Mexican States, is the legislature of the federal government of Mexico consisting of two chambers: the Senate of the Republic and the Chamber of Deputies. Its 628 members meet in Mexico City.