The Mexico Department ( Spanish: Departamento de México) was a department during both periods of the Centralist Regime of Mexico in the 19th century, first existing between 1835 and 1846, ^[1] and again between 1853 and 1856. ^[2]

The Mexico Department was created on 23 October 1835 as a move prior to the replacement of the federal system in place since 1824 for the centralist system, ^[1] which was formally implemented through the Seven Laws promulgated on 30 December 1836. ^[3] The department consisted of what was the State of Mexico, the federal district and the Tlaxcala Territory; its capital was Mexico City. ^{[1] [4]} It dissolved on 22 August 1846, when it returned to the federal system and the departments became states again. ^[2]

With the ascension of Antonio López de Santa Anna to power, the federal states lost their autonomy and became departments again, confirmed with the decree of 22 April 1853; the established organization was short lived, since on 1 March 1854 the Plan of Ayulta dictated a repeal of centralism, though the Centralist Regime lasted until 15 May 1856, ^[2] when the departments were supplanted by the previous states.

• Territorial evolution of Mexico