VENICE: The party of the year is happening here: the fresco-adorned Aman hotel on Venice's Grand Canal is feverishly preparing for George Clooney's wedding to Amal Alamuddin, his Lebanon-born British fiancee.

Hollywood stars and the world's paparazzi have already begun arriving for the nuptials of the world's most sought-after catch, who will, sources said, celebrate with 136 guests at the exclusive seven-star hotel in the 450-year-old Palazzo Papadopoli.

The pair are expected to be officially married in a civil ceremony on Monday, but the city of masks is preparing for a weekend of serious partying before then.

“Clooney's on everyone's lips here in Venice, the girls in particular are all in a tizzy, they'll be lining the banks of the canal to see him,” said watertaxi driver Bruno Bartolini, who said it would be “a fantastic party.""

George Clooney (L) and his Lebanon-born British fiancee, Amal Alamuddin (C) holding a bag bearing the logo A&G (Amal and George ) arrive at Venice's Piazzale Roma in Venice. -Photo by AFP

“The city's ground to a halt because they're using the grand canal, but what does that matter: there's nothing better than getting married in Venice, “Bartolini said.

Guests including Brad Pitt, Angelina Jolie, Sandra Bullock and Matt Damon are set to stay at the Hotel Cipriano on the island of Giudecca, where they are expected to dine in style Friday evening with the groom and his glamorous bride-to-be.

Rome's former mayor Walter Veltroni, a long-term friend of Clooney's, will be performing the civil ceremony, which is likely to be held in the town hall, the stunning Ca' Farsetti 14th century palace opposite the Aman hotel.

US actor George Clooney takes a taxiboat upon his arrival in Venice, on the eve of his wedding. -Photo by AFP

The streets around the town hall will be off limits to the public from 12 noon (1000 GMT) for two hours on Monday, when the ceremony is expected to take place.

Amal Alamuddin, fiancee of George Clooney, arrives in Venice, Italy. -Photo by AFP

The reception will take place on Saturday at the luxurious water-front Aman, where guests will be escorted by police boats keen to keep over-excited Clooney admirers and hundreds of photographers at a distance.

They'll be met with lashings of fizz and canapes in the garden, an oasis sheltered from the bustle of the canal, before sitting down in the main library to a sumptuous five-course dinner rustled up by a renowned Italian chef, according to a source close to the hotel.

The Aman's restaurant will be then transformed into a nightclub, where they'll dance the night away, a source said.

Though the world's most famous waterway will not be closed entirely, there were grumbles in the northern Italian city over the disruption caused by the wedding and such an ostentatious display of wealth in times of economic crisis.

Nevertheless, all are desperate for a glimpse of the erstwhile bachelor in his Armani suit and Alamuddin in an Alexander McQueen creation designed by Sarah Burton, the woman behind the gown worn by Britain's Kate Middleton at her wedding to Prince William in 2011.

Alamuddin, who moved to Britain with her family as a three-year-old, is a top human rights lawyer who met the Hollywood star through his humanitarian work.