Deep Breath is taking place at St David's Hall in the Welsh Capital, attended by Peter Capaldi and Jenna Coleman, alongside showrunner Steven Moffat.
Moffat told BBC Radio Wales he believes Capaldi's Doctor will go down well with fans.
He's a brand new, slightly shocking, extremely funny, charismatic Doctor, and it's that wonderful thing - he's very, very different and yet he's exactly the same. That's is the thing about the Doctor, the Doctor is always kind of the same, but you couldn't have a bigger contrast to the Matt Smith version.BBC Wales director Rhodri Talfan Davies said:
Doctor Who is getting even bigger and even better - and it's a real thrill that the show's fans here in Wales will be the very first to see the new Doctor at this very special premiere screening. Doctor Who has been made in Wales for almost 10 years - and we're so proud of its worldwide success.A further screening takes place later today on London's South Bank, before the team head of to Seoul at the start of their dash around the world.