A prequel to the hit fantasy series – entitled House Of The Dragon – is coming and it has been reported that a sequel is also in the pipeline and that Harington will be in it.
Asked about it by the BBC, Clarke said: “He has told me about it. And I know it exists. It's happening."
"It's been created by Kit as far as I can understand, so he's in it from the ground up,” she went on.
“So what you will be watching, hopefully, if it happens, is certified by Kit Harington."
However, it seems Clarke is unlikely to reprise her Game Of Thrones role of Daenerys Targaryen.
Asked if she was up for a spin-off, the 35-year-old replied: "No, I think I'm done."
Game Of Thrones started on HBO in 2011 and was a massive success, airing until 2019.
Earlier this month, The Hollywood Reporter said the network had entered into “early development” on a sequel to the series that would focus on fan favourite Jon Snow.
The report said that if the series moved forward, Harington was attached to the project and would reprise the role.
House Of The Dragon – which is set 200 years before the events seen in Game Of Thrones and will follow the Targaryen family – is set to be unveiled this August.
Read more: Kit Harington set to star in a Game Of Thrones spin-off sequel