Mexico was a country to the south of the United States. While it was never annexed as Canada was, the US, seeking to protect business interests and their oil supply, put a lot of pressure on Mexico in 2051 and finally invaded it, though presumably never annexed it.
The Fallout non-player character Tycho had traveled to Mexico. The Fallout: New Vegas companion Raul Tejada was born in Mexico and witnessed the Great War destroy Mexico City. A small group of Mexicans also made their way into Zion Canyon, in Utah, but were savagely murdered by the infected members of the Vault 22 expedition.
- 2042 - A major earthquake takes place in Mexico City. The Mister Handy general construction robot becomes the leader in sales in Mexico. (source: Mr. Handy design document)
- 2051 - Seeking to protect business interests and their oil supply, the United States began to exert increasing pressure on Mexico, citing the political instability and pollution stemming from Mexico as a threat to the United States. Various economic sanctions served to destabilize Mexico, and the United States military entered Mexico to keep the oil refineries running and ensure that oil and fuel continued to make their way north across the border (at Mexico's expense). (appears in the Fallout Bible timeline)
- October 23, 2077 - Mexico is nuked, along with most of the planet. Mexico City is hit and destroyed by nuclear weapons.
- Some time after the war - New California Republic takes over Baja, although does not have enough control to annex it into the Republic.
- 2281 - New California Republic sends Rangers to Baja and sends troops from there to the Mojave Wasteland.
- 2066 - Resource rioting occurs in Denver, and riots happen because of that. Midwest USA and Mexico start having food shortages and can't supply Denver with the food it needs. Food riots occur (presumably in Denver). National Guard called in. (source: Denver design document)
- The Mexican flag appears in Fallout: New Vegas wrapped around the stock of the unique hunting rifle, Paciencia.
- Bombay Jack
- Raul Tejada
- Tuco Benedicto Pacifico Juan Maria Ramirez