"Miss Middleton wished for her dress to combine tradition and modernity with the artistic vision that characterises Alexander McQueens work," officials said in a statement.
"Miss Middleton worked closely with Sarah Burton in formulating the design of her dress."
They said the dress made with ivory and white satin gazar, with a train measuring 2.7 metres (8.8 feet) and lace sleeves, "epitomises timeless British craftsmanship".
The bride had also borrowed a tiara loaned to her by Prince William's grandmother, Queen Elizabeth II.
Burton took over as creative director at the label after McQueen committed suicide in February 2010. She had previously worked side by side with him for 14 years.
The 36-year-old graduate of Central St Martin's had long been tipped as the wedding dress designer.
A woman wearing a studded leather belt doubled through the loops of her jeans, in a fashion identical to the one favoured by Burton, was photographed on Thursday evening slipping into the Goring Hotel where Kate was staying.
Her head was hidden under a huge fur hat in an attempt to avoid identification.
The dress is expected to spawn a thousand reproductions.
Elizabeth Emanuel, who created Diana's fairytale wedding gown in 1981 with her husband David, is still being asked to make copies of that gown, an ivory silk taffeta frock with a 25-foot (7.6-metre) long train.
"Exactly as it happened in 1981, there are going to be people watching as she walks down the aisle with their sketch pads, with the machinists and pattern cutters all ready and waiting. By the next morning you'll see copies in the high street," Emanuel said.