The most recent saint canonized by Pope Francis was Joseph Vaz who was elevated to the altars on January 14, 2015.
Saint John Paul II, who died in 2005, is the most recent living saint. He was just canonized in 2014.
St. Andre Bessett was canonized on October 17, 2010, one of the six most recent saints.
The most recently canonized Mexican saint is Saint Jose Sanchez del Rio. He was canonized by Pope Francis in 2016 and is known for his bravery and faith during the Cristero War in Mexico in the 1920s.
Saint Joseph Vaz who was canonized by Pope Francis on January 14, 2015, at Galle Face Green, Colombo, Sri Lanka.
On April 27, 2014, Pope John XXIII and Pope John Paul II were canonized in the Vatican by Pope Francis. As of October 28, 2014, these are the most recent canonizations.
The list of canonizations changes every few months so, rather than posting a name of an individual only to have it change, click on this link for the most recent names of canonized saints.
There are several saints named Sergius so you need to be specific. Most were Precongregational Saints and never officially canonized. They were declared as saints by the early Christian community and not by the pope.
On Sunday, October 21, 2012, Kateri Tekakwitha and Marianne Cope of the United States were canonized in Rome. At Mass for the Seventh Sunday of Easter (May 12, 2013), Pope Francis canonized two Latin American religious Foundresses, Mother Laura Montoya e Upegui - the first Colombian saint - and Mother Maria Guadalupe Garcia Zavala, from Mexico. One from North America and one from South America but Americans nonetheless.
Mexico was the most recent inquiry.
St. Thomas Aquinas was canonized as a saint in 1323 by Pope John XXII, about 49 years after his death in 1274.
Saint John was one of the twelve apostles of Jesus, and known to be the one most beloved by Christ. The apostles weren't canonized, but became saints, nonetheless. Therefore, there is no known date of when he became a saint.