Sisi is to meet Pope Francis at 1330 GMT on the first Vatican visit by an Egyptian leader in eight years, officials said.
He will then meet Italian Prime Minister Matteo Renzi at 1800 GMT, Renzi's office said.
Sisi, who was then army chief, ousted president Mohamed Morsi, the country's first freely elected leader, in July 2013, prompting a wave of deadly violence between security forces and Morsi's supporters that drew rebukes from Europe and the United States.
But boosted by its increasingly central role in combating Islamist militancy, Egypt has come in from the cold since Sisi won a presidential election in May after crushing both Islamist and secular opponents.
Officials said the four-day tour, which will also take him to France, is also aimed at securing European investment in the Egyptian economy, which has been battered by political turmoil since the Arab Spring uprising of 2011.