Archbishop of Buenos Aires, Argentina Cardinal Jorge Mario Bergoglio has been named pope. His new title is Francis I.
Earlier, White smoke poured from the roof of the Sistine Chapel and the bells of St. Peter's Basilica pealed, signaling that cardinals had chosen a new pope to lead the troubled Roman Catholic Church after only five ballots.
The decision by 115 cardinal electors came sooner than many faithful expected because of the large number of possible frontrunners identified before the vote to replace Pope Benedict, who resigned in February.
The name of the new leader of the world's 1.2 billion Roman Catholics was expected to be announced in around half an hour from the central balcony of St. Peter's Basilica.
The secret conclave began on Tuesday night with a first ballot in the Renaissance splendor of the chapel and four ballots were held on Wednesday. The white smoke indicated the new pontiff had obtained the required two thirds majority in the fifth ballot.
Following a split ballot when they were first shut away amid the chapel's Renaissance splendor on Tuesday evening, the cardinal electors held a first full day of deliberations on Wednesday. Black smoke rose after the morning session to signal no decision.
Cheers arose from hundreds of people sheltering from incessant rain under a sea of umbrellas in St. Peter's Square as the white smoke billowed from the narrow chimney.
The cardinals had faced a tough task in finding a leader capable of overcoming crises caused by priestly child abuse and a leak of secret papal documents that uncovered corruption and rivalry inside the Church government or Curia.
The wave of problems are thought to have contributed to Pope Benedict's decision to become the first pontiff in 600 years to resign.
Additional report from Reuters