The couple reportedly picked the date, despite it being a time when the weather can be iffy, because that's when Prince Harry has two weeks off from his military duty.
William's secretary said the prince and his fiancée are very much in charge of the arrangements for the big day, but Middleton's family is throwing an engagement party.
William and Kate ended days of suspense by choosing Westminster Abbey, a grand venue where members of the House of Windsor have been crowned, married, mourned and buried. The abbey was also the site of the funeral for William's beloved mother, Princess Diana.
Palace officials said the two were on "cloud nine" with their wedding choice and want the nation to share their joy.
"We know that the world will be watching on the 29th of April, and the couple are very, very keen indeed that the spectacle should be a classic example of what Britain does best," said William's private secretary, Jamie Lowther-Pinkerton.
The big question, of course, is what Kate will wear. London bookies are putting their money on designer Phillipa Lepley being chosen to create the all important dress.
The Associated Press contributed to this story.