Mattarella, who had initially been reluctant to sign up for a second term, received an astounding 55 rounds of applause from an otherwise divided parliament as he delivered his speech.
The 80-year-old was welcomed in the chamber of deputies – decorated with red drapes and 21 tricolour flags – by the 1009 “grand electors” who voted in the presidential election along with Prime Minister Mario Draghi and members of the government.
“We still need to work together to strengthen Italy, beyond the current difficulties,” Mattarella said in his speech to parliament.
The president also referred to the situation in Ukraine, where Russian troops have massed on the border, and called for a peaceful solution to the crisis.
“We cannot accept that now, without even the pretext of competition between different political and economic systems, the winds of confrontation are once again blowing across a continent that has experienced the tragedies of the First and Second World Wars,” he said.
Crowds lined the streets of the Italian capital as Mattarella was driven from the Quirinal Palace to parliament flanked by carabinieri officers on motorbikes.
The swearing of the oath was marked with a 21-gun salute from the cannon on Rome’s Janiculum Hill and the Montecitorio bells resounded across the city.
Mattarella, who is from Sicily and is a former government minister, has won the respect of Italians with his quiet, unassuming manner and calm handling of repeated political crises and the health emergency.
In Italy’s political system, the president is a powerful figure who gets to appoint prime ministers and is often called on to resolve political crises.
Governments in the euro zone’s third-largest economy survive around a year on average.
