Jos de la Cruz Porfirio Daz Mori ( or ; Spanish: [pofijo i.as]; 15 September 1830 2 July 1915), known as Porfirio Daz, was a Mexican general and politician who served seven terms as President of Mexico, a total of 31 years, from 28 November 1876 to 6 December 1876, 17 February 1877 to 1 December 1880 and from 1 December 1884 to 25 May 1911. The entire period from 1876 to 1911 is often referred to as Porfiriato and has been characterized as a de facto dictatorship.A veteran of the War of the Reform (18581860) and the French intervention in Mexico (18621867), Daz rose to the rank of general, leading republican troops against the French-imposed rule of Emperor Maximilian. He subsequently revolted against presidents Benito Jurez and Sebastin Lerdo de Tejada, on the principle of no re-election to the presidency. Daz succeeded in seizing power, ousting Lerdo in a coup in 1876, with the help of his political supporters, and was elected in 1877. In 1880, he stepped down and his political ally Manuel Gonzlez was elected president, serving from 1880 to 1884. In 1884 Daz abandoned the idea of no re-election and held office continuously until 1911.Daz has been a controversial figure in Mexican history. His regime ended political turmoil and promoted economic development. He and his allies comprised a group of technocrats known as Cientficos, "scientists". His economic policies largely benefited his circle of allies as well as foreign investors, and helped a few wealthy estate-owning hacendados acquire huge areas of land, leaving rural campesinos unable to make a living. In later years, these policies grew unpopular due to civil repression and political conflicts, as well as challenges from labor and the peasantry, groups that did not share in Mexico's growth.

Despite public statements in 1908 favoring a return to democracy and not running again for office, Daz reversed himself and ran again in the 1910 election. His failure to institutionalize presidential succession, since he was by then 80 years old, triggered a political crisis between the Cientficos and the followers of General Bernardo Reyes, allied with the military and with peripheral regions of Mexico. After Daz declared himself the winner of an eighth term in office in 1910, his electoral opponent, wealthy estate owner Francisco I. Madero, issued the Plan of San Luis Potos calling for armed rebellion against Daz, leading to the outbreak of the Mexican Revolution. After the Federal Army suffered a number of military defeats against the forces supporting Madero, Daz was forced to resign in May 1911 and went into exile in Paris, where he died four years later.

The president of Mexico (Spanish: Presidente de México), officially the president of the United Mexican States (Spanish: Presidente de los Estados Unidos Mexicanos), is the head of state and head of government of Mexico. Under the Constitution of Mexico, the president heads the executive branch of the federal government and is the commander-in-chief of the Mexican Armed Forces. The current president is Andrés Manuel López Obrador, who took office on 1 December 2018.

The office of the president is considered to be revolutionary, in the sense that the powers of office are derived from the Revolutionary Constitution of 1917. Another legacy of the Mexican Revolution is the Constitution's ban on re-election. Mexican presidents are limited to a single six-year term, called a sexenio. No one who has held the post, even on a caretaker basis, is allowed to run or serve again. The constitution and the office of the president closely follow the presidential system of government.