The tour will take place after the current series of Strictly concludes, and will run between January 18 and February 10.
Judges Craig Revel Horwood, Len Goodman and Bruno Tonioli will also join the tour as judges, alongside Kate Thornton.
The tour will take in the Birmingham NIA, Newcastle Arena, Glasgow SECC, Liverpool Arena, London O2 Arena, London Wembley Arena, Sheffield Arena, Nottingham Arena and Manchester Arena.
Riley said of the tour: "I've had an absolute ball on the show and the chance to carry on dancing, and in front of thousands of people, is too good to miss. Roll on January!"
Harmer added: "I'm really thrilled to be part of the Strictly Tour, I'm looking forward to bringing some of the glitz and glamour to the fans all over the country.
"The competition on tour will be just as tough as it is on TV, so I hope to win plenty of votes from the arena audiences."
Vaughan also spoke enthusiastically of the tour, saying: "Learning so many different dances has been a huge challenge for me, but an amazing experience. I'm really looking forward to testing myself with the new routines we'll be performing on the tour."
This series has been the most popular run of the dancing show yet, achieving a high of 10.5m viewers for the latest results show, and widening the gap over reality rival The X Factor.
A full list of tour dates can be found at the official Strictly Come Dancing Live website.
Photo gallery - Strictly Come Dancing week six: