Bezos and Sánchez arrived at the five-star hotel on Wednesday to prepare for their wedding celebrations.
Photos shared on social media showed Bezos waving from a water taxi as he and Sanchez arrived at the dock of the hotel with two security boats in tow.
Set in Palazzo Papadopoli, one of the city's eight monumental palazzos on the Grand Canal, Aman is one of the most luxurious hotels in Italy.
Bezos, the world's third-richest billionaire ranked by Forbes, and American journalist Sánchez have rented the hotel for their wedding, which is expected to take place between June 26 and 28.
Guests who had previously booked rooms for Wednesday night were reportedly removed after Bezos rented the entire hotel a few months ago, according to Page Six.
The wedding is estimated to cost between $15 million and $20 million, with around 200 guests, including members of the Trump family, Katy Perry, Oprah Winfrey, and Kim Kardashian, CNN reports.
Ahead of the couple's arrival, 10 to 12 security personnel conducted a sweep of the property on Tuesday, checking cabinets and the courtyard.
"Rococo artwork is balanced by the contemporary elegance of Jean-Michel Gathy interiors, while rare private gardens are complemented by opulent dining venues and spacious suites," the hotel's website reads.
The hotel's rooms, signature rooms, and suites, which vary in size and configuration, feature works by some of Italy's greatest artists, including 16th-century architect Sansovino and 18th-century painter Tiepolo.
Contemporary furnishings complement authentic silk wall coverings, chandeliers, wood paneling, chinoiserie and painted ceilings, with many rooms offering Grand Canal views.
Room rates start from US$1,600 a night, according to online hotel booking agencies.
Aman suites (pictured) are the most spacious retreats in the palazzo, each offering a distinctive ambiance.
The Grand Canal Suite enchants with views of the Grand Canal and an abundance of natural light, while the Alcova Tiepolo Suite exemplifies 18th-century Rococo splendor, adorned with Tiepolo’s original frescoes, theatrical murals, and gilded ceilings.
Guests can dine in the sumptuous space on the piano nobile, enjoy a private celebration in one of the palazzo's hidden rooms, or, during the warmer months, dine in the canal-side garden, a rarity in Venice.
