Wednesday's appearance was their first together in Rome in the days before their wedding Saturday, reportedly to be held in a castle overlooking Lake Bracciano.
Cruise wore a dark gray, pinstriped suit with matching vest and a striped lavender tie as he escorted Holmes, who was clutching what appeared to be a very sleepy baby girl dressed in a fuzzy-soft white sweater, white tights and print dress.
The couple, who became engaged in June 2005, are the parents of a daughter, Suri, who was born April 18.
Holmes, 27, wore a dark jacket over what appeared to be a dark skirt or dress as she crossed a cobblestone square atop ancient Capitoline Hill.
Mayor Walter Veltroni is a big movie buff and was the driving force behind Rome's first international film festival this year, and speculation quickly grew that the Hollywood couple was paying a courtesy visit to him.
The major of Bracciano, Patrizia Riccioni, said she met with Tom and Katie in private, gave them a little gift and, on behalf of the town, welcomed them with open arms, reports CBS Newspath correspondent Charlie D'Agata.
2Cruise and Holmes were first photographed together in Rome in April 2005. Two months later, the "Mission: Impossible" star announced that he had proposed to Holmes atop the Eiffel Tower in Paris.
The 44-year-old actor had been spotted by photographers Tuesday as he was being driven from his hotel atop the Spanish steps. Cruise had flown into Rome on Monday, and airport officials said Tuesday that Holmes was also in the city.
Residents around the imposing 15th-century Odescalchi Castle, which is rumored to be the venue for the wedding, have been rushing to rent out windows and terraces overlooking the mansion to the media who have been pouring into the location near Rome.
One theory is that Tom and Katie will arrive in Bracciano via the lake, D'Agata reports. Then they have the option of sneaking in this side door. Or, for a big entrance, they can follow this road directly to the castle's main gate, where fans and the media will be waiting.
The Bracciano City Hall, which appears to be one of the better-placed locations for viewing, is renting the windows of a nearby building with a view on the main entrance of the castle for $1,280. Prices for other homes conveniently placed near the castle include a bargain $255.
In one case, though, the prices were not so reasonable: A private terrace overlooking the likely route of the nuptial motorcade and the castle's internal parking lot was offered to a TV news agency for a $128,000.
Some of Hollywood's top stars have already arrived for the event, including Jim Carrey, Jennifer Lopez, and Brooke Shields.
As far as the big day itself on Saturday, a few details are starting to slip out — like 6,000 rose- and coffee-scented candles.
But what the day will taste like is still top-secret — as Cruise has reportedly slapped a million-dollar gag order on caterers. To add a little spice, the locals have even cooked up a special risotto inspired by Katie and Tom.
"Cruise control," as they call it in Hollywood, is sure to rev up even more before the $9.5 million weekend wedding premieres.