2018 Mexican general election

General elections were held in Mexico on 1 July 2018. Voters elected a new President of Mexico to serve a six-year term, 128 members of the Senate for a period of six years and 500 members of the Chamber of Deputies for a period of three years. It was one of the largest election days in Mexican history, with most of the nation's states holding state and local elections on the same day, including nine governorships, with over 3,400 positions subject to elections at all levels of government. It was the most violent campaign Mexico has experienced in recent history, with 130 political figures killed since September 2017.

The incumbent president Enrique Peña Nieto was not constitutionally eligible for a second term. Incumbent members of the legislature were term-limited, thus all members of Congress were newly elected. As a consequence of the political reform of 2014, the members of the legislature elected in this election will be the first allowed to run for reelection in subsequent elections. The National Electoral Institute (INE) officially declared the new process underway on 8 September 2017.

The presidential election was won, by a landslide margin of almost 31 points, by Andrés Manuel López Obrador of the National Regeneration Movement (MORENA), running as the candidate of the Juntos Haremos Historia alliance. This is the first time a candidate won an outright majority (according to official vote counts) since 1988, and the first time that a candidate not from the Institutional Revolutionary Party (PRI) or its predecessors has done so since the Mexican Revolution. In addition, it was the first time an alliance of political parties (excluding PRI) backing a single presidential candidate won majorities in the Senate and Chamber of Deputies. This election also marked both the worst electoral defeat suffered by the PRI and the worst electoral defeat for a sitting Mexican government since universal suffrage was adopted in the country in 1917.