Pope Francis opened his pontificate with an unexpected visit to a basilica in Rome for prayer.
The 76-year-old was elected last night during the second day of deliberations in the conclave.
He is the first Pope from the Americas and the first Jesuit at the helm of the worldwide Catholic Church.
Pope Francis went to the Basilica of St Mary Major early on Thursday morning and stayed half an hour to pray.
Although Pope Francis told the crowds in St Peter's Square last night that he was going to "pray to the Madonna so that she may protect Rome", the visit to the basilica was unscheduled and, according to Vatican News, surprised local residents and children on their way to a nearby school.
He was due to return to the Sistine Chapel for a special private Mass with the cardinals.
The election of Pope Francis has been warmly welcomed by Catholics, who have spoken of their admiration for a man who is intelligent as well as humble, and who holds a special regard for the poor.
Cardinal Timothy Dolan, Archbishop of New York, spoke warmly of how after being elected, Pope Francis travelled with the cardinals in a minibus instead of by motorcade.
Expectations are high that the election of the first Latin American Pope will mark the start of a positive shake up for the Catholic Church, which has been dogged by abuse scandals in recent years.
The UK's Catholic leaders expressed their delight in the election of Pope Francis. Archbishop Vincent Nichols, President of the Catholic Bishops' Conference of England and Wales said: "As he begins his new Apostolic ministry, as the Bishop of Rome and Shepherd of the universal Church, Pope Francis I may be assured of the prayers and loving support of the Catholic community throughout England and Wales."
His election has been welcomed not only by Catholics, but the leaders of other Churches.
The Archbishop of Canterbury Justin Welby offered the new Pope "every blessing" and said his election was "of great significance to Christians everywhere".
"I look forward to meeting Pope Francis, and to walking and working together to build on the consistent legacy of our predecessors," he said.