Norton also reveals his very favourite guests that he has already had on the show. And no, it isn't who you're thinking of...
It is difficult to imagine that there is any celebrity left on Earth that Graham Norton hasn't interviewed.
The Graham Norton Show has been around since 2007, but he even had his OG chat show So Graham Norton on Channel 4 from way back in 1998.
We're talking about nearly a quarter of century of interviews, with each episode housing three or four or more celebrities at a time.
So when he was asked which celebrity he has never interviewed but would love to, it would make sense that he would have to go way, way back for his answer.
At the Dublin launch for his latest novel Forever Home, which is where he also gave a new answer for the worst guest he's ever had on his show, Norton revealed the one person he would have loved to chat to:
"I would have been happy to just have met her, or just being in the same room – it would be Lucille Ball, who was just an amazing, amazing person. And actually, it's interesting, her legacy is kind of being reinvented now. Last year there was a couple of documentaries about her, and then there was that film [Being The Ricardos, with Nicole Kidman as Ball].
"I love her," Norton continued. "My favourite story about her is apparently if you're having dinner in her house, so you're all sitting around having dinner, and then if someone went to the toilet, when they came back, Lucille would say 'There she is, tell her to her face!'
"I do that all the time now."
Norton was also asked about his favourite guests that he has already had on the show, telling the audience:
"I would go back to the early days of the show, when people took a chance on us. We weren't tried and tested, and it looked like quite a scary show back on Channel 4. Because we used to have those sex websites and dildos in baskets and things.
"The guests were always quite protected from that, but if a celebrity was watching television, they might think 'I'm not doing that'.
"So a big up to people like Joan Collins, or Dolly Parton, or Cher. Who were really early people, they came on when no-one was coming on. So I'll be forever grateful to them."
We genuinely thought his favourite might be Miriam Margolyes, but that might be just because she still has such a special place in our hearts...
