The ex-Conservative MP will be partnered at the shows with Strictly judge and the tour's creative director Craig Revel Horwood.
Speaking about the upcoming jaunt, Widdecombe said: "I am very much looking forward to dancing with Craig, after all the rude remarks he has made. However, as he is even taller than Anton, the result should be even funnier! Will anyone judge his performance, I wonder?"
Horwood added: "Watching Anton carry Ann round the dance floor like a pantomime dame has been rather painful, but never the less extremely entertaining!
"Ann is a good sport, I can't wait to get my hands on her, and create a fabulous routine which people will talk about for many years to come!"
Widdecombe joins a previously announced lineup, which includes Matt Baker, Colin Jackson, Patsy Kensit, Jimi Mistry, Tina O'Brien, Kara Tointon, Pamela Stephenson and Ricky Whittle.
Zoe Ball is hosting the tour, which kicks off at Nottingham Trent FM Arena on January 14.