The duo will join Fern Britton, Lisa Riley, Louis Smith, Michael Vaughan and Dani Harmer for the three-week-long jaunt next January and February.
Van Outen is competing in Strictly's current series, while Tufnell appeared on the 2009 edition, making him the only person on the tour not part of the 2012 cast.
"I've had the time of my life on Strictly Come Dancing and can't wait to take the show on the road, dancing in front of a huge live audience, night after night," Van Outen said.
"I'm so glad my Strictly dream doesn't have to end yet."
Tufnell commented: "Just when I thought it was all over! I can't wait to join the Strictly Come Dancing 2013 live tour and see what this year's celebrities have got. They don't stand a chance."
The Strictly national tour kicks off on January 8, 2013 at Birmingham's National Indoor Arena.
It will then come to Newcastle, Glasgow, Liverpool, Manchester, London's O2 and Wembley Arenas and Nottingham, before concluding at Sheffield's Motorpoint Arena on February 10.