He has revealed he's spent 12 months secretly battling prostate cancer.
The TV veteran confirmed he underwent a life-saving operation in January and is now cancer-free.
Fry, 60, tweeted a 12 minute video, with the caption: "For the last 2 months I’ve been in the throes of a rather unwelcome and unexpected adventure.
"I’m sorry I haven’t felt able to talk about it till now, but here I am explaining what has been going on."
In the clip, the QI star revealed he had the surgery in the first week of January and is now on the road to recovery as the cancer "doesn't seem to have spread."
He aid: "[I] had the op first week in January. There it is - it doesn't seem to have spread.
"One option was radiotherapy but it's a long process.
"The other was to get rid of the prostate by sending little robots in through tiny holes in the stomach.
"They took the prostate out, and eleven lymph nodes. It was an aggressive little bugger.
"If you're wondering why I've been out of the public eye - I'm sure you haven't - I wanted to recover out of the public eye."
He added: "Cancer is a word that rings in your head: 'Good heavens Stephen, you're not supposed to have cancer'.
"You don't think it to happen to you - cancer is something happens to other people.
"For the moment I'm fit and well and happy."