The Congress of Mexico (formally: 'el Congreso de la Unión' or Congress of the Union) is the legislative branch of the Mexican government. Its structure and responsibilities are defined in Articles 50 to 79 of the 1917 Constitution of Mexico.

The Mexican Congress is bicameral – that is, it is composed of two chambers. The upper chamber is the Senate (Cámara de Senadores or Senado). The lower house is the Chamber of Deputies (Cámara de Diputados).