The LXV Legislature of the Congress of the Union (65th Congress) was a meeting of the legislative branch of Mexico, composed of the Chamber of Deputies and the Senate of the Republic.

It convened on 1 September 2021, and ended on 31 August 2024, during the final three years of President Andrés Manuel López Obrador's presidency.

The Chamber of Deputies was elected in the 2021 legislative election, in which Juntos Hacemos Historia, consisting of the National Regeneration Movement (Morena), the Labor Party (PT), and the Ecologist Green Party of Mexico (PVEM), kept their majority but did not reach the two-thirds supermajority required to pass López Obrador's proposed constitutional reforms.

[3] These tables relate to the composition of the Senate of the Republic and the Chamber of Deputies at the start of the LXV Legislature and present day and summarises the changes in party affilation that took place during the congress.

The third corresponds to the senator who secured a seat through first minority.