With the stunning backdrop of the snowy peaks of Gstaad, their guests will enjoy a weekend of celebrations, with some arriving from Wednesday, January 29, reports HELLO!'s sister publication HOLA!
Some 300 friends and family are expected, with the guests of honour being the couple's ten-month-old son Sacha, Andrea's mother Princess Caroline and sister Charlotte Casiraghi.
Excitement is high among royal watchers since this is Charlotte's first big event since the birth of her own son Raphael with partner Gad Elmaleh.
Andrea and Tatiana are hosting a religious ceremony in Gstaad
The bride and groom have picked the region's exclusive hotels – the Palace, the Bellevue, Gran Park Hotel and The Alpina – to accomodate their invitees.
These will reportedly include Prince Nikolaos and Tatiana of Greece, Uma Thurman and her partner Arpad Busson and fashion heiress Margherita Missoni. Not to mention Prince Albert, the principality's reigning sovereign and his wife Charlene.
Eggli restaurant which will host a fondu party
Andrea, 29, and Tatiana, 30, themselves will be based in the £14,000-a-night 'Panorama' suite of The Alpina, a duplex spread over 400 sq metres, comprising three bedrooms, its own private kitchen and a terrace with spectacular mountain views.
Gstaad has been chosen for the festivities because the bride, who is a Colombian heiress, grew up in Switzerland until the age of 15.
On Friday, the Casiraghis are holding a fondu party at the world renowned Eggli restaurant. After this, there will be an opportunity for everyone to ski down the mountain by torchlight.
A candle-lit ceremony will take place the next day at 7pm in the 11th-century convent of Rougemont. It was built by monks from the Order of Cluny and became famous because Princess Diana attended finishing school nearby.
The Monaco royals are expected to attend in force
Andrea, who is second in line to the throne of Monaco, will arrive accompanied by his mother. The groom's party will also include his siblings – Charlotte, Pierre with his beautiful Italian girlfriend Beatrice Borromeo and Princess Alexandra of Hanover from his mother's third marriage.
In keeping with Tatiana's romantic vision, she will walk down an aisle lined with hundreds of white roses to the strains of Ave Maria, played on a 19th-century organ.
The bride will make her entrance on the arm of her brother Julio Mario Santo Domingo. Normally known for her hippy chic style, the mother of one is thought to have opted for a more formal choice for her second wedding gown. She has reportedly commissioned Valentino for one of his fairytale designs.
With their vows exchanged, the couple will leave for a wedding dinner at the Palace hotel in a horse-drawn carriage, wrapped in white furs.
The party will go on into the small hours with music organised by Julio Mario, a well-known New York DJ. Festivities will wrap up with a brunch on Sunday, also at the Palace.