Óscar Arnulfo Romero y Galdámez (15 August 1917 – 24 March 1980) was a prelate of the Catholic Church in El Salvador. He served as Auxiliary Bishop of the Archdiocese of San Salvador, the Titular Bishop of Tambeae, as Bishop of Santiago de María, and finally as the fourth Archbishop of San Salvador. As archbishop, Romero spoke out against social injustice and violence amid the escalating conflict between the military government and left-wing insurgents that led to the Salvadoran Civil War. In 1980, Romero was fatally shot by an assassin while celebrating Mass. Though no one was ever convicted for the crime, investigations by the UN-created Truth Commission for El Salvador concluded that Major Roberto D'Aubuisson, a death squad leader and later founder of the right-wing Nationalist Republican Alliance (ARENA) political party, had ordered the killing.

In 1997, Pope John Paul II bestowed upon Romero the title of Servant of God, and a cause for his beatification was opened by the church. The cause stalled but was reopened by Pope Benedict XVI in 2012. Romero was declared a martyr by Pope Francis on 3 February 2015, paving the way for his beatification on 23 May 2015. During Romero's beatification, Pope Francis declared that his "ministry was distinguished by his particular attention to the most poor and marginalized." Pope Francis canonized Romero on 14 October 2018.