Pope Leo XIV was elected as the Catholic Church's 267th leader on Thursday.
The temporary chimney atop the Sistine Chapel released a plume of white smoke on Thursday evening local time, signaling that the 133 cardinals working inside had reached a two-thirds majority to elect a new pope for the Catholic Church.
American Cardinal Robert Prevost was shortly thereafter announced as the 267th pontiff. He chose the name Leo XIV, a senior cardinal deacon announced.
The 69-year-old Chicago native is the first American pope and is seen as a diplomat in the church.
"This is the first greeting of the risen Christ. May the peace be with you," Leo said in Italian in his first remarks as pope. "This is the peace of the risen Christ."
Tune in to "The American Pope: Leo XIV," a special edition of "20/20," streaming now on Hulu and Disney+.
Former President Joe Biden, the second Catholic president and active churchgoer, issued a statement about Pope Leo on X.
"Habemus papam - May God bless Pope Leo XIV of Illinois," Biden wrote. "Jill and I congratulate him and wish him success."
-ABC News' Oren Oppenheim
Former President Barack Obama shared his praise for Pope Leo in a tweet Thursday.
"Michelle and I send our congratulations to a fellow Chicagoan, His Holiness Pope Leo XIV. This is a historic day for the United States, and we will pray for him as he begins the sacred work of leading the Catholic Church and setting an example for so many, regardless of faith," he said.
-ABC News' Brittany Shepherd
Chicago Mayor Brandon Johnson called Prevost's selection "the greatest moment in the history of the greatest city," highlighting that the new pope was "born in Chicago, educated in Chicago, came back and served this city."
Johnson praised the new pope, saying he "recognizes and understands the value of immigration." The last pope to be named Leo, XIII, was known as the "Pope of Labor," and Johnson called Chicago the most pro-worker city in America.
Like the mayor, the new pope is reportedly a Chicago Cubs fan. Johnson said Chicagoans to tend to "take some partisanship," as "everyone has to know exactly who to root for -- but today, the world is rooting for Pope Leo."
"Today is truly a remarkable day" for Chicago and the world, Johnson said.
The Rev. Father Vito Crincoli told ABC News that the new pontiff's name selection of Leo follows a line of "strong popes."
"Leo XIII loved his people. He considered man not a machine. A man's work was a reflection of his dignity. This pope, we don't know this yet, but it would be really interesting to see why he took the name Leo," Crincoli said.
Crincoli also noted Pope Leo, a native to the South Side of Chicago, "loves" deep dish pizza.
