Romero entered the minor seminary in San Miguel at the age of thirteen.
From the hospital they were released from Cuban custody and sailed on to Mexico, then traveled overland to El Salvador.
He promoted various apostolic groups, started an Alcoholics Anonymous group, helped in the construction of San Miguel's cathedral, and supported devotion to Our Lady of Peace.
Latin American church groups often proclaim Romero an unofficial patron saint of the Americas and El Salvador; Catholics in El Salvador often refer to him as "San Romero", as well as "Monseñor Romero".
Outside of Catholicism, Romero is honored by other Christian denominations including Church of England and Anglican Communion through the Calendar in Common Worship, as well as in at least one Lutheran liturgical calendar.
In 1974, he was appointed Bishop of the Diocese of Santiago de María, a poor, rural region.
On 23 February 1977, Romero was appointed Archbishop of San Salvador.
He was later appointed rector of the inter-diocesan seminary in San Salvador.
Emotionally and physically exhausted by his work in San Miguel, Romero took a retreat in January 1966 where he visited a priest for confession and a psychiatrist.
Archbishop Romero is also one of the ten 20th-century martyrs depicted in statues above the Great West Door of Westminster Abbey in London.
In 2008, Europe-based magazine A Different View included Romero among its 15 Champions of World Democracy.
Hailed as a hero by supporters of liberation theology inspired by his work, Romero, according to his biographer, "was not interested in liberation theology" but faithfully adhered to Catholic teachings on liberation and a preferential option for the poor, While seen as a social conservative at his appointment as archbishop in 1977, he was deeply affected by the murder of his friend and fellow priest Rutilio Grande a few weeks after his own appointment and subsequently developed into an outspoken social activist.