The five-room suite at the Goring Hotel was renovated just for her visit and features a four-poster bed, silk wallpaper and even a waterproof flat screen TV above the bathtub.
The palace said the 5-star hotel was the bride's personal choice.
There's also word that Middleton had three different gowns made for the wedding, just in case the actual design got out.
Prince William and Middleton will marry at Westminster Abbey on April 29.
The Associated Press contributed to this story.