The BBC have today announced that the Doctor's new companion will be Jenna-Louise Coleman.
Here is part of the press release (which you can read in full here)
Jenna-Louise Coleman has beaten hundreds of hopefuls to become the new companion to Doctor Who, it was announced today by Steven Moffat.
Twenty-five year old Jenna from Blackpool will star alongside the 11th Time Lord, Matt Smith, to mark the biggest year in the show's history.
Best known for her roles in Emmerdale (Jasmine Thomas) and Waterloo Road (Lindsay James), Jenna will replace Karen Gillan when she and Arthur Darvill bow out of the show in a heartbreaking departure after one final series of rollercoaster voyages later this year on BBC One.
Jenna says: "I'm beyond excited, I can't wait to get cracking; working alongside Matt I know is going to be enormous fun and a huge adventure."
The Doctor will meet his new friend in a dramatic turn of events as the show builds towards its enormous, climactic 50th anniversary year - full of thrills, adventures and big surprises. Series seven is currently filming and comprises 14 big, blockbuster-movie episodes - each a brand new epic adventure featuring new monsters and some familiar foes as you've never seen them before.
Lead writer and Executive Producer, Steven Moffat, says: "It always seems impossible when you start casting these parts, but when we saw Matt and Jenna together, we knew we had our girl. She's funny and clever and exactly mad enough to step on board the TARDIS.
Jenna-Lousie's character will appear for the first time in the 2012 Christmas Special.
Congratulations Jenna-Louise & welcome to the show.