Mexico
Mexico — also called New Spain — was a nation in North America. It was located to the northwest of Venezuela. Its eastern coastline looked out over the Gulf of Mexico with Jamaica and Cuba located to the east from the coastline. (TV: War of the Sontarans)
History
Prehistory
Circa 65 million BC, Briggs' freighter crashed into Mexico's surface (PROSE: Cat's Cradle: Time's Crucible) with Adric on board, killing him and causing the extinction of the dinosaurs. (TV: Earthshock)
Early history
Circa the 15th century, the First Doctor, Susan, Ian Chesterton and Barbara Wright visited what would become Mexico. Barbara attempted, and failed, to alter the history of the Aztecs. (TV: The Aztecs)
Cherub implied that he had seen what Mexican Indians could do to a man's eyelids with a knife. (TV: The Smugglers)
19th century
In 1855 of an alternate timeline, "Mexico or New Spain" was noted on a British map of the world. (TV: War of the Sontarans)
20th century
In June 1911, Iris Wildthyme, Edwin Turner, Jenni Marcel and Zack Hoffman briefly visited Mexico. Whilst there, they saw Pancho Villa. (AUDIO: Kronos Vad's History of Earth (Vol. 36,379))
The War Lords kidnapped several soldiers from the Mexican Civil War for their War Games. (TV: The War Games)
In 1941, during the Day of the Dead, psychotic artist Susini attempted to create sculptures from the flesh and bone of living humans. Her plot was defeated by the Eighth Doctor and local artists Frida Kahlo and Diego Rivera. (COMIC: The Way of All Flesh)
The 1968 Olympics were held in Mexico. (TV: The Underwater Menace)
In 1994, the Seventh Doctor, Ace and Bernice Summerfield visited Mexico, meeting Cristián Xochitl Alvarez and investigating Huitzilin and the "Blue". (PROSE: The Left-Handed Hummingbird)
21st century
In the early 21st century, the United States fought a war with Mexico. (PROSE: Cat's Cradle: Warhead)
The Torchwood Institute was aware that a small time rift was present in Mexico. (COMIC: Shrouded) Following his encounter with Torchwood Three, Captain John Hart left to reside in Mexico. (TV: Exit Wounds)
In 2011, Tony suggested that the day staff at the San Pedro Overflow Camp were illegal immigrants from Mexico. (TV: The Middle Men)
As of 2012, Guerrero, Oaxaca, Chiapas, and Calakmul were locations in Mexico that held conservation tours. Jo Jones planned to attend one of these tours. (AUDIO: The Infinite Today)
In the 2010s, the Mexico border was among the places where newly-hatched Zygons were settled across the world as part of Operation Double, resulting in a minority of Zygons residing in New Mexico under the pretence of being British migrants. (TV: The Zygon Invasion)
In 2017, Ramirez Harmon was the President of Mexico. (AUDIO: Army of Death)
Undated events
K9 Mark II once went on tour to Mexico with So Solid Crew. (PROSE: K9)
Parallel universes
In Pete's World, there existed a state called the United States of Mexico. It covered the Grand Canyon. (PROSE: Lumic)
Notable individuals' ties to Mexico
Mexico was the birthplace of would-be dictator Ramón Salamander. (TV: The Enemy of the World)
Former Time Agent John Hart based himself out of Mexico after moving to 21st century Earth. (COMIC: Shrouded)
Other references
The Sixth Doctor promised Evelyn Smythe that he would go to Mexico or Havana to pick up some specialty chocolate for her to use if she agreed to travel with him. (AUDIO: The Marian Conspiracy)
The Eleventh Doctor attempted to take Amy Pond and Rory Williams to Mexico to see the Day of the Dead festival. He was not successful. (TV: A Town Called Mercy)
Yasmin Khan, a British woman of Pakistani heritage, was mistaken for being Mexican by an ignorant waitress in 1955 Alabama. (TV: Rosa)
The Fourteenth Doctor uses Mexico as one of the codewords used to restore Donna Noble's memories of her adventures with the Tenth Doctor and unleash The DoctorDonna in order to stop the Meep from wreaking destruction in London. (TV: The Star Beast)