Some prominent U.S. Catholic leaders praised the historic moment over the weekend as they welcomed the president-elect.
During his victory speech Saturday night, Biden -- who regularly attends Mass and has long been open about his faith -- quoted Ecclesiastes 3:1-3 from the Bible.
"To everything there is a season: a time to build, a time to reap, and a time to sow and a time to heal," he said. "This is the time to heal in America."
He also ended his speech by quoting the Catholic hymn "On Eagle's Wings" to underscore his message of unity and healing.
"And now together on eagles' wings, we embark on the work that God and history have called us to do with full hearts and steady hands, with faith in America and in each other, with love of country, a thirst for justice," he said. "Let us be the nation that we know we can be -- a nation united, a nation strengthened, a nation healed."
Father James Martin, who delivered the closing benediction at the Democratic National Convention and serves as an adviser to Pope Francis, tweeted that Biden's use of the hymn made his phone "buzz like crazy."
"This means four years of not only a Catholic president, but an injection of #Catholic culture into our national conversation in a way probably not seen since JFK," he tweeted.
John F. Kennedy became the first Catholic president when he was elected in 1960.
In 2015, Biden told the weekly Jesuit publication America Magazine that he shared a lot of the pope's doctrine.
"He's the embodiment of the Catholic social doctrine I was raised with," Biden said of Francis. "The idea that everyone is entitled to dignity, that the poor should be given special preference, that you have an obligation to reach out and be inclusive."
Despite the historic nature of his presidential run, Biden did not have a landslide victory with Catholic voters, according to ABC News' exit polls. Roughly 51% of respondents who identified as Catholic voted Democratic in this year's election, according to the poll. Some conservative Catholics who disagree with Biden on issues like abortion voted instead for President Donald Trump.
Last year, a priest in South Carolina denied Biden communion due to the former vice president's stance on abortion.
Biden, however, received commendations from Catholic leaders after he was declared the winner of the election Saturday.
Sister Simone Campbell, head of the Catholic social justice lobby group NETWORK and leader of "Nuns on the Bus," said in a statement that Catholics aren't one-issue voters.
The U.S. Conference of Catholic Bishops, which represents all the nation's bishops, also congratulated Biden and Vice President-elect Kamala Harris in a statement and called for unity among Americans.
"Democracy requires that all of us conduct ourselves as people of virtue and self-discipline," the statement said. "It requires that we respect the free expression of opinions and that we treat one another with charity and civility, even as we might disagree deeply in our debates on matters of law and public policy."