The 17-time Grand Slam champion tweeted Monday, "ciao tutti, I just arrived in bella Italia! Looking forward to Rome."
Federer's first opponent at the Foro Italico is slated to be 47th-ranked Jeremy Chardy.
Federer and wife Mirka were already parents to twin daughters when they announced the birth of twin boys, Leo and Lenny, six days ago — prompting him to withdraw from the Madrid Open.
Rome is one of only three Masters titles that Federer hasn't won, and it's the last key clay-court warmup for the French Open, which starts in two weeks.
Federer reached the Rome final for the third time last year.