Cardinal Bergoglio chose the name Pope Francis I. The 76-year-old Archbishop of Buenos Aires has spent nearly his entire career in Argentine overseeing churches and priests.
He's the first pontiff ever from the Americas and from outside Europe in more than a millennium.
Bergoglio was trained as a chemist. He also taught literature, psychology, philosophy and theology before becoming the Archbishop of Buenos Aires in 1998.
Locals say he was wearing his own cross and looked very humbled in his appearance.
"I actually knelt down when he blessed us. i was watching at my computer station at my desk and I did pray for him and I am praying for him he has a very tremendous role," says Theresa Prymuszewski, St. Ann Catholic Church.
He became a Cardinal in 2001, and reportedly received the second highest number of votes after Joseph Ratzinger in the 2005 Papal Election.