The Rome event is one of more than 60 ‘sister' marches being held around the world in solidarity with the Women's March on Washington the same day.
Hundreds of thousands of people are expected to attend the Washington march, which was set up by a retired lawyer to protest Trump's inauguration. As well as the multiple marches in the US, events are being held in European cities including London, Paris, Brussels, Berlin, Geneva and Copenhagen.
The global event is not intended to be an exclusively anti-Trump march but a show of support for civil rights, and is supported by 200 progressive groups representing issues including legal abortion, affordable healthcare, voting rights, racial equality and the environment.
Speaking to The Local, Elizabeth Farren, one of the organizers of the Rome march, said: "This march is relevant in Italy because Italy is in no way immune to the populist wave that elected Trump."
Farren said that the march was open to all supporters of civil rights, including men, women, Italians and foreigners. The aim, she said, is "to show the world that those who support progressive values are a force to be reckoned with, and that they will not remain silent if their rights and values are threatened".
She also commented on the strong ties between Italy and the US, both cultural and economic, and expressed concern that some of Trump's proposed policies could have a negative influence overseas. "If the US decides that women's rights are no longer important, that immigrants should be expelled, that walls should be built and so on, why should Italy be immune to such influence?"
The march intends to "send a bold message" to Trump's administration and to others, to show "that our vibrant and diverse communities are the strength of our societies", organizers stated.
The Rome event will begin at Piazza della Rotonda, by the Pantheon, at 11am on Saturday. This means it will take place slightly before the American march, a decision organizers said they made in order to ensure it could be held in daylight hours and that participants travelling from further afield could make transport arrangements.
Groups from all over Italy, including Florence and Milan, are travelling to the capital to take part in the event, alongside Romans, expats and holidaymakers.
One attendee who lives in Princeton, New Jersey but is travelling to Rome in January, said she was looking forward to the Italian event. "I am delighted to have this rally so that I can express many fears and concerns," she said.
Another American said that she was participating in the Washington march, and was "thrilled" that her daughter, who is currently studying in Rome, could take part in the global movement.
Farren she was unsure of exactly how many people would attend, but expected hundreds of people to take part; over 400 people have replied to the Facebook event already.
"We hope to have many more by the week's end, and to fill up the piazza," she said.