The Pope has written to Joe Biden telling him to work for peace and reconciliation both in the US and internationally.
In his letter, Pope Francis said he was praying for Biden, a Catholic, to have "wisdom and strength" while in office.
He also expressed his hope that the American people would "continue to draw strength from the lofty political, ethical and religious values that have inspired the nation since its founding".
Biden has promised to be a "president for all" in the face of entrenched divisions across the US over issues like racial injustice and polarized party politics.
He also takes office at a time when the US is struggling to bring down Covid numbers, with over 24 million cases to date and more than 400,000 deaths.
The Pope urged Biden to remember the poor and vulnerable, and work for the common good over the next four years.
"At a time when the grave crises facing our human family call for farsighted and united responses, I pray that your decisions will be guided by a concern for building a society marked by authentic justice and freedom, together with unfailing respect for the rights and dignity of every person, especially the poor, the vulnerable and those who have no voice," he said.
"I likewise ask God, the source of all wisdom and truth, to guide your efforts to foster understanding, reconciliation and peace within the United States and among the nations of the world in order to advance the universal common good.
"With these sentiments, I willingly invoke upon you and your family and the beloved American people an abundance of blessings."