Actors Tom Cruise and Katie Holmes have flown to the Maldives for their honeymoon after exchanging vows at their wedding in a 15th-century castle north of Rome on Saturday.

Italian singer Andrea Bocelli serenaded Cruise, 44, and Holmes, 27, afterwards, according to Cruise's publicist, Arnold Robinson.

Katie Holmes and Tom Cruise were married by a Scientology minister at a 15th-century castle in Italy.
(Robert Evans/Associated Press)

Holmes wore a fitted Giorgio Armani off-the-shoulder bridal gown with a train of ivory silk, lace and beaded crystal embroidery. Cruise wore a handmade Armani tuxedo at the ceremony presided over by a Scientology minister.

Cruise's best friend, David Miscavige, was best man, and Holmes's sister, Nancy Blaylock, was the matron of honour.

The couple, who have a baby daughter, Suri, landed in Italy earlier this week ahead of their wedding at Odescalchi Castle in the town of Bracciano, 43 kilometres north of Rome.

Holmes arrived at the castle a couple of hours ahead of her groom, holding seven-month-old Suri close and dressed in a black dress and black boots.

Victoria Beckham, formerly known as 'Posh Spice' of the pop group the Spice Girls and the wife of British soccer star David Beckham, poses in Rome before heading to the wedding.
(AP)

The sun was shining as Cruise arrived wearing sunglasses. Fans shouted "Tom, Tom!" as he waved from the back seat of a van.

Some 6,000 candles lined the entrance to the castle, its towers and windows. The wedding and reception reportedly cost $2.5 million US.

Celebrities on the guest list included actors Will and Jada Pinkett Smith, soccer star David Beckham and his wife, Victoria, Jennifer Lopez, Marc Anthony, Mission Impossible: III director J.J. Abrams, director Steven Spielberg and actors John Travolta, Richard Gere, Russell Crowe, Kirstie Alley, Brad Pitt, Angelina Jolie and Jim Carrey.

Notably, actress Brooke Shields was also invited. Shields and Cruise had a public spat over her use of anti-depressants for postpartum depression. The two made up earlier this year.

Guests were to receive gift bags filled with luxury items such as designer sunglasses and towels monogrammed with the couple's initials.

Onlookers gather outside Odescalchi Castle in Bracciano, north of Rome.
(Gregorio Borgia/AP)

The castle, which can host up to 1,400 guests, is adorned with six towers, gardens and a nearby chapel. The medieval structure also has a library with a frescoed ceiling and a loggia looking out on the lake. It was also the location of the 1998 wedding between CNN foreign correspondent Christiane Amanpour and James Rubin, then the spokesman for the U.S. State Department.

Hundreds of photographers as well as residents and fans crowded in front of the town's square outside the castle.

Police were seen patrolling the walls of the castle and all vehicles were banned from the centre of town.

Bracciano residents celebrate nuptials

"This is the most exciting thing that has ever happened here," said Bracciano resident Deborah Nardone, 18. The town of 14,000 was transformed Saturday by the throngs of paparazzi and helicopters hovering overhead.

Some 6,000 candles decorated the entrance, towers and windows of the castle. The wedding and reception reportedly cost $2.5 million US.
(Massimo Percossi/AP)

One café had a sign which read: "Wishing you love and happiness."

A restaurant in the town was offering a "Tom e Kat" — a basket of parmesan cheese with truffles and mushrooms.

Scientology weddings include traditional elements such as rings and vows as well as a pledge never to go to bed without talking about any differences or problems.

Steps were taken to make marriage legal

The ceremony also stresses a tenet known as ARC: A for affinity, R for reality and C for communication.

The Scientology rite is not legally recognized in Italy and would have to be preceded or followed by a civil union. Cruise's publicist said "the required steps were taken for the marriage to be legal."

Cruise was once married to Nicole Kidman, with whom he adopted two children — they were among the 150 people attending the wedding. The Australian actress sent her ex-husband and Holmes an expensive vase, wishing them a "lifetime of happiness."

Kidman married country crooner Keith Urban in a lavish event in Sydney, Australia, in March. Urban recently entered alcohol rehabilitation.

With files from the Associated Press