Wilson, a Calgary-based entrepreneur who spent three seasons as a panelist on the CBC series, tweeted the news Monday.
"Yup — my cancer is back — but w/ 2 months of radiation & all sorts of other modalities I will be #KickingCancersAss," he wrote, also including the hashtag #CanadianThanksgiving.
In a prior tweet, he wrote he was "grateful for having beaten cancer 13 years ago — & for the opportunity to be #KickingCancersAss again."
Wilson, 57, was diagnosed with prostate cancer in 2001.
He co-founded brokerage firm FirstEnergy Capital in 1993 before going on to become a philanthropist and bestselling author. He departed "Dragons' Den" in 2011.
Wilson was not immediately available for comment Tuesday.