The This Morning host will be joining Mollie King and Davood Ghadami in the BBC dance competition
Revealing the news on This Morning, she said: "I haven't even had a chance to tell my mates at Loose Women!"
Eamonn Holmes added: "I'm so excited to watch you every week!"
In a statement, Ruth said: "I have dreamt about doing Strictly for so long, I can't quite believe my dream has come true!
"The sum of my dance experience is throwing a few shapes at a party, I've never had a dance lesson in my life.
"Without doubt it will be the scariest yet most exciting thing I've ever done.
"It'll be a welcome change worrying about my next hot move instead of my next flush!"
She'll be joining Mollie King and Davood Ghadami in the BBC dance competition.
The reveal came after Ruth confessed earlier in the show: "I was once called 'Too fat for Strictly!'"
They'd been teasing which This Morning family member would be on Strictly this year for the whole show.
And Ruth and Eamonn said the This Morning star was going to walk out of one of three doors, throwing in names like Dr Chris and Deirdre.
But it was Ruth who walked out!
Former Strictly professional Karen Hardy was also on This Morning to give Ruth some advice.
She told Eamonn: "You need to be her rock!"
And she added to Ruth, "it's all about the hips".
Ruth confessed she's worried about the "hard work".
Eamonn also added she's "flat out" with work at the moment, and he's worried whether they'll be food on the table for him if she's going to be spending all her time dancing.
In a slight dig at his wife, Eamonn added: "You're going to be an inspiration for old women all over the country!"
And Rylan Clark shrieked: "I'm so excited my telly mum is going to be on Strictly!"
*This Morning continues on ITV1 weekdays at 10.30amRead more at mirror.co.uk