So, the wait is over - the actor playing the eleventh Doctor has been revealed as Matt Smith.
He's 26 years old and is the youngest Doctor Who ever.
Unfortunately this topic is now closed but there are Comments pages on other subjects on the main Chat index.
"I love David Tennant!! What's wrong with you people!!!! When we found out David Tennant was leaving, we were literally crying. I don't think anyone will be as good as David."
Charlotte, 11, Western Australia, Australia
"Why, why, why, why, why??? He just looks freaky, and his hair is totally NOT cool. He will never replace David Tennant - I'm really going to miss him. Maybe I'll have to reconsider my Saturday nights while Matt's around..."
Cerys, 12, Cheltenham, England
"I don't like him. He was talking a lot and he is boring, unlike David Tennant who I actually want to listen to. I hate his hair, it's like it flopped to one side. I don't even want to watch after David Tennant leaves!!"
Sumaya, 13, London, England
"David Tennant was better than him! He is really young and hasn't got enough experience. He will never fill David Tennant's shoes! I've never even heard of him before!"
Melissa, 11, Manchester, England
"What kind of choice was that?! He's far too young! Have you gone mad? The only Doctor that will ever be the Doctor is David Tennant. Keep him or you will lose fans!"
Ellie, 11, Preston, England
"I was really upset and annoyed when David Tennant announced he was leaving!!! And then Matt Smith is the 11th Doctor!! I mean come on!! He looks evil!!"
Amy, 13, Devon, England
"I think Matt Smith is the wrong choice. A) because he's only 26, B) Because hardly anyone's ever heard of him and last of all C) he has a stupid haircut. PLEASE MAKE DAVID TENNANT COME BACK!"
Emily, 10, Hertfordshire, England
"I was gobsmacked when I found out that David Tennant was leaving. He kept me glued to the TV screen every Saturday night throughout the past three series. Matt is too young to be the Doctor. I mean he'll be 27 by the time he comes in so I think David Morrissey should do it. He was brilliant in the Christmas special. Please change your mind and pick someone teenagers and kids would actually know about!"
Sally, 14, Leicester, England
"I'm really going to miss David and I don't really know about Matt (I haven't heard about him until now). He doesn't seem to have as much personality as David, but in 2010 we'll all find out. David Tennant will always be my Doctor."
Nathalia, 15, Illinois, America
"I'm worried that the next Doctor is not going to be as brilliant as the 10th (David Tennant). But we have to wait and see what the future brings."
Amy-Louise, 13, UK
"I think Matt will be good, but he will not be as good as David Tennant. He is the best Doctor ever."
Robert, 10, Staffordshire, England
"Why did they have to get rid of David Tennant? He rocks! They must be crazy if they think that he will be as popular and he isn't even that good looking. I am so not watching it in 2010!"
Ruby, 11, London, England
"Weak hair and I don't think he will be very good. My mum and dad love him, but I hate him. David Tennant was the best and always will be!!!"
Ami, 10, West Yorkshire, England
"I think Matt Smith would make quite a good Doctor because he's young and he's fresh, and if he had a companion they could form a stronger relationship, or fall in love or something like that!"
Sophie, 12, West Sussex, England
"Rupert Penry-Jones would have been better than the new actor Matt Smith."
Georgina, 12, London, England
"We should give Matt a chance, but I think that David Tennant will always be the best! He is a legend! I think Matt will be a darker Doctor, but I don't like his hair!"
Alex, 15, West Yorkshire, England
"I think that he will make a great Doctor but I don't think he will be as good as the past Doctors (mainly David Tennant). My mum and dad think that he will be a great Doctor; me, my sister and my mates think he will be rubbish."
Laura, 11, Orlando, America
"Don't judge him until you've seen him in action! Lots of past Doctors have been quite old, the BBC is trying to go in a new direction, and that's good. He won't be as good as David Tennant, and he isn't very popular right now, but the BBC made David into a huge star, now let them do the same for Matt. Give the newbie a chance."
Jacob, 12, Essex, England
"I don't think he will do very well. And if you are trying to appeal to a younger audience you aren't doing very well."
Kenny, 9, Wokingham, England
"Why is everyone complaining about his hair? I think it looks cool!"
Lauren, 12, Lancashire, England
"I think he is OK, but David T was much better. He will always be my fave."
Zoe, 11, London, England
"I do not like the new Doctor because he is not going to be as good as David Tennant."
Tiffany, 12, Nottinghamshire, England
"I'm really sad David Tennant is leaving, I think he was good at playing The Doctor. The new Doctor seems a bit young but he might be good, who knows. But I still wish David wasn't leaving."
Charlotte, 13, England
"What about the Doctor's daughter? Has everybody forgotten about her?"
Lilly, 14, Newcastle, England
"I saw Matt in Ruby in the Smoke and I thought he was really good. I think he'll make a good Doctor, but only time will tell."
Hannah, 15, Orkney, Scotland
"I think he is a bit too young to play the title role, but I would have preferred somebody more popular. If he becomes more famous in the future and gets older I think he would be a brill actor to play the title role."
Liam, 12, Coventry, England
"I'm sad about David Tennant leaving the show, but he has to leave eventually. I think the new Doctor should be quite good. He seems very young, but it should be good to have a different type of Doctor. I cant wait to see him in 2010!"
Kate, 14, Glamorgan, Wales
"How can you say he's rubbish if you haven't seen him perform yet? I think it'll be great to get a new face as The Doctor because although David Tennant was good, he was getting a bit boring. And his hair is actually quite cool."
Ellie, 13, Luton, England
"No no no no no no!! This can't be happening!!"
Rebecca, 11, Manchester, England
"I watched Matt Smith in Ruby in the Smoke and he was excellent. Even though I am sad to see David Tennant leave the show, it will be interesting to see what Matt Smith brings to it. Like David Tennant, he just looks like a Doctor Who natural!"
Chloe, 14, Liverpool, England
"I saw Matt in The Sally Locket Mysteries and thought he was quite good. But as the new Doctor I'm not quite sure if he'll be good or not! I think it's sad that David is leaving!!"
Lauren, 11, Cardiff, Wales
"David Tennant should stay! No-one could replace David!"
Emily, 9, Tyne and Wear, England
"I don't like the new Doctor. I think that David Tennant should stay. He is the best!!"
Aki, 13, Birmingham, England
"I think Matt will be a good Doctor because he has one of those looks where you don't know what he is going to do next."
Hannah, 13, England
"To be honest, he seems great. Not as good as David Tennant but he'll be the second best Doctor ever."
Matt, 10, Norfolk, England
"I think Matt Smith will be good but he will never replace David Tennant."
Robbie, 8, Hertfordshire, England
"I think Matt Smith looks like a pretty good Doctor, but David Tennant was the best Doctor there's been because he's so crazy and really funny. I wonder what it would be like if the Doctor was a female...?"
Nina, 12, Glamorgan, Wales
"When I first saw him on the TV I was a bit worried because he looked quite young. Then when you see him acting in the clips they showed, I thought he looked quite good. He has already worked with Billie Piper, that's very good, though I will really miss David Tennant!"
Anna, 11, London, England
"I think he would make a good Doctor but I still prefer David Tennant."
Bobby, 9, Chester, England
"I think it's going to take some time to get used to him."
Elinor, 7, Bedford, England
"I don't like the new Doctor because David Tennant made it more interesting."
Billy, 9, Oxfordshire, England
"He's very creepy but he looks good."
Katy, 11, Burnley, England
"He doesn't look fit for the job."
Matthew, 11, Croydon, England
"I am going to miss David, But Matt, he looks good...but...I sort of don't like his hair."
Rosa, 10, London, England
"He is so cute, I can't wait until 2010."
Joanna, 11, Dublin, Ireland
"I think Matt Smith is an excellent choice for the new Doctor. All the previous Doctors have been a bit older but I think Matt Smith will show some youth on an old show. Plus I think his hair is GREAT!!!!!!"
Samantha, 13, Middlesex, England
"I'm not really bothered as long as it's him and not a woman, that would be really odd."
Tommy, 11, London, England
"I... I... I'm out of words... in a very bad way!!!!"
Jacob, 9, Gloucestershire, England
"It will be a shame to see David go, he was so brill, but Matt looks great and seems to fit the part, although we haven't seen him act yet!!!!"
Marie, 12, Hong Kong
"I think he looks creepy and sinister!"
Erin, 14, Lisburn, Northern Ireland
"I think Matt Smith will be a cool Doctor."
Ollie, 13, Inverness, Scotland
"I think David Tennant was a really brilliant Doctor so it will take some time to get used to Matt Smith."
Juliet, 10, Sunderland, England
"I really didn't want David Tennant to go because I thought he was a really good actor. But I'm going to give Matt Smith a chance before I judge him."
Ffion, 13, Gwynedd, Wales
"He looks scary..... and he has a bad haircut! No-one can replace Tom Baker, Christopher Eccleston and David Tennant. But you never know, he could be good."
Becca, 11, Harrow, England
"I think he's got the hair for it, but Matt looks a bit too young. It's good that he's unknown because we won't know how he will act. Every Doctor was different and I can't wait to see him in action, but I will really miss Tennant."
Karima, 11, Northampton, England
"When I first saw him I was a bit disappointed because I expected him to be more well known, but then they showed clips of him acting, and I realised that actually, he could do an amazing job. Good luck Matt!"
Megan, 13, Lincoln, England
"I am happy that there is a new Doctor because I didn't like the other one."
Sergio, 13, Alicante, Spain
"I think he'll do really well as the Doctor, but I still think that David Tennant is the best for the comedy!"
Mary, 12, Leeds, England
"David Tennant is still the best Doctor ever. I bet Matt Smith will be a good 11th Doctor. Not sure about the fringe though!!!"
Suhera, 14, London, England
"I think that Matt may be too young. Being the Doctor takes a lot of work and I don't think he will be up to the job."
Laura, 11, Durham, England
"He looks really weird. I think he will suit the part of the Doctor, but he won't be as good as David! He looks more like 30 than 26."
Charley, 14, London, England
"I think he will be good but not as good as David Tennant."
Katie, 10, Norwich, England
"I think this new Doctor will be rubbish. He looks too young to play the part. David Tennant has been the best Doctor so far! BRING HIM BACK."
James, 14, Liverpool, England
"He looks fab and I think he is better looking than David Tennant. I don't think my mum will like him as much as DT!"
Eloise, 9, Glasgow, Scotland
"I think he looks quite interesting because he's young, he will probably be exciting and kind of wacky - I can't wait until the new Doctor Who comes out!"
Leila, 11, West Sussex, England
"I wanted someone I had heard of because I don't know if he is going to be good or not. He does look very young."
Holly, 13, Brighton, England
"WHAT? He's far too young to be a Doctor. Anyway, who is he??"
Lucy, 9, London, England
"I really liked David Tennant and I don't really think Matt looks the part, but I'm sure he will be a fabulous doctor!!
Rosie, 11, Halifax, England
"He looks better than Tennant to me. He looks young and old at the same time. He also looks mischievous and wise so I have high expectations for him."
Dan, 12, Croydon, England
"I don't like the idea of him as the new Doctor but that is probably just because I am such a big fan of David Tennant as Doctor Who. I think that Matt has a tough act to follow and everybody will be comparing him."
Rebecca, 14, Kent, England
"I think that it's a bad idea that Matt Smith should be the next Doctor, David Tennant is fantastic and cannot be replaced, David was a great Time Lord!"
Hinna, 12, Surrey, England
"I think it's a good thing because it's a new Doctor and 26 is a cool age."
Phoebe, 8, East Sussex, England
"I'm pleased that I finally know who the next Doctor is going to be, but also sad as I love David Tennant. I've heard that Matt Smith is a great actor too, so I hope that Doctor Who stays great. In a way it would be cool for somebody really famous to get the part so everybody could say 'oh that's so and so from so and so!' but I also think somebody unknown is good as it's more exciting to see how he acts."
Mima, 13, Plymouth, England
"I think he will be a new Tom Baker. Wacky but brill!"
Jessica, 13, Chester, England
"I think Matt is absolute perfection. I'm really glad he's so pale because I am too and it needs to be cool again! My older sister really fancies him hahaha."
Katie, 10, Sheffield, England
"I think he looks older than 26, so age isn't a barrier. I've seen him act and I wasn't sure until I realised what he was in. He'll be a good Doctor - I think - but we'll just have to wait and see!"
Ella, 12, Edinburgh, Scotland
"I think he'll do great. I really liked him in The Ruby In The Smoke and The Shadow In The North and he seems the right sort of person for the job."
Beth, 13, Bradford, UK
"I don't think people are giving Matt Smith a chance. When they first revealed David Tennant, I didn't like him, but I preferred him to Christopher Eccleston in the end, so I think everybody should reconsider Matt Smith and wait until he starts."
"Matt Smith plays Jim in The Ruby in the Smoke! So, he's like worked with Billie Piper! And he's not too young! He looks young but in some ways he looks OLD! Like a perfect Doctor! I've got high expectations!"
Sally, 13, Bedford, UK
"I didn't want David Tennant to leave, I loved him! I don't think that Matt Smith really looks the part of the new Doctor - but I am sure the director of the show will make him even better than all of the Doctors!"
Holly, 13, Brighton, England
"I think that the 11th Doctor (Matt Smith) will be brilliant! He looks wacky and wise at the same time and I have heard he is a great actor as well. Good luck to him!!!!! :)"
Helena, 11, Isle of Wight, England
"I think he'll be fantastic. He has that Doctor-ish look about him, and he's not famous but a brilliant Doctor, and I think he has something special."
Ruthie, 13, London, England
"I think he'll be ok but no one is going to be as good as David Tennant. I HATE the hair though!"
Izzy, 11, Oxfordshire, England
"I think that he seems like a really good actor, but from the pictures they have released he seems to be bringing a darker, edgier side to the Doctor, which I'm not quite sure about yet."
Vicki, 14, Cambridge, England
"I don't want to decide whether I like him or not before I have seen him as the Doctor. However I just don't think he will be right. I liked him in other things so I'm hoping my first impression is wrong."
Sarah, 13, Bishops Stortford, England
"The new Doctor scares me. He looks more like a villain than a good guy. HOW IS HE SUPPOSED TO BE A DOCTOR??????? I might have second thoughts about watching the next series of Doctor Who!"
Marianna, 12, London, England
"I think he is a great Doctor. My dad made a set for Matt once!!!! Matt is going to be brill cause people don't know him."
Ava, 10, Nottingham, England
"I think he is a bit too young. But I'm glad it's a man not a woman. I cant say he'll be rubbish coz I've never seen him act."
Becky, 13, London, England
"I look forward to watching the new Doctor. I have never seen him before but I think he will be good."
Thomas, 8, Mount Gambier, Australia
"I think that Matt Smith doesn't quite fit the look of the Doctor, but then again that's what I thought of David Tennant and Christopher Eccleston when they first started, so the more we see of them the more they begin to look the part."
Hannah, 11, Belfast, Northern Ireland
"I am really disappointed with the choice. I think he is too young to play a 900-and-something-year-old alien. The viewers should get to decide who becomes the next Doctor. If that happened we wouldn't have this waste of a regeneration!"
Laura, 13, Leeds, England
"No way! The Doctor Who team made an awful, awful mistake. This has put me off watching it!"
Peggy, 12, Dundee, Scotland
"I bet you are going to be the best Doctor so far."
Megan, 10, Nottingham, England
"WHAT? He's too young... who is he???"
Sean, 12, Swindon, UK
"David Tennant really shouldn't have gone, he was the best Doctor, no question. Matt Smith could be good, but he should work on a less freaky smile, a tan and a better haircut. Apart from that I have no idea what he will be like and can only say that he will have some seriously big shoes to fill in!!!"
Sophie, 12, Riverhead, England
"I think he will be great! Because he is young I think he will bring a real edge to the role. I really like David Tennant but I can't wait to see how Matt does. I would have liked a woman though..."
Zoe, 12, Wolverhampton, UK
"I don't think we should judge him until we see him on screen as the Doctor."
Lowri, 13, Caerphilly, South Wales
"I really didn't want David to leave, he was the best Doctor ever! but I don't know what Matt Smith will be like. Maybe they'll change the Doctors Earth name from John Smith to Matt Smith!!!"
Sophie, 12, Riverhead, England
"I think it will be interesting how he will make the Doctor his own. Of course David did a fantastic job, but I think it was the right time for him to move on. Good luck Matt!!!! Nice hair!!"
Zoe, 14, North Walsham, England
"He looks absolutely brilliant. Even the hair. It makes a different Doctor - like very other actor has with their approach as playing the Doctor."
Eve, 11, Stockport, England
"I think he's perfect because he has a sort of eerie look about him which is kind of spooky. I think he'll be great"
Casey Jane, 10, Newark, England
"I think it is good to have a doctor who isn't really famous, as David and Chris weren't very famous before their roles as the Doctor. I look forward to series five."
Mel, 11, Swansea, Wales
"If you haven't seen his acting, you can't have an opinion. I have, and I think he's brilliant : D"
Callum, 12, Fife, Scotland
"I am not a big Doctor Who fan but he will never be as good as David Tennant. And I agree with a few people there, what's with the hair :S? It's a disaster waiting to happen even thinking about him as the Doctor. No offence dude who is the 11th Doctor."
Courtney, 12, Bristol, England
"Well, nobody knows for sure what Matt Smith will be like as the Doctor. We just gotta wait untill 2010 so we will know if he is the true Doctor! His haircut is very, ummm, strange. I hope he's gonna be good!"
Helena, Nearly 13, London
"Well I thought Donna was going to be rubbish, but she proved me wrong so I will have to wait and see before making judgements. Besides we won't see him till 2010."
Rosie, 12, Chester, England
"I think he will be good, most young people have never heard of him and that was the same with David Tennant. It will be good to see what he can do. Can't wait!"
Dominic, 14, Reading, England
"It'll be interesting to see what he'll be like as the 11th Doctor. He's not famous so that's good, because if there was someone famous being the Doctor it wouldn't work. We'd just think of one of their other roles, not them as the Doctor. Age doesn't really matter, it's about their way of acting, and what they bring to the role."
Caitlin, 14, Trelawnyd, North Wales
"I have two words for the studio bosses, 'Oh Dear!!' He looks nothing like a Doctor and will definitely not be able to fit into David Tennant's shoes! I would have rather it be a woman!"
Katie, 14, Manchester
"I think he might be good but lose the stupid haircut!"
Bob, 14, Great Missenden, England
"He looks awesome! I think his hair looks really cool. I think he will make a fantastic doctor. :)"
Tom, 14, Chesterfield, England
"I think Tom Chambers would have been good as the new Doctor. He is sweet, funny and has a nice approach. I think he would be great. Matt Smith will be RUBBISH."
Nicola, 9, Northampton, England
"I think he's ok but I really think he should lose the weird haircut."
Sabrina, 11, Wooten Basset, England
"No! He's too young. A 26-year-old just doesn't fit. They have to have that bit of age that gives them the maturity to play Dr. Who!"
Lola, 11, Torquay, England
"I'm not sure about the new Doctor, although in my opinion I think he is too young for the role. But since I haven't seen him acting as the Doctor I don't want to make a decision if he makes a good Doctor or not."
Sara, 13, Welwyn Garden City, UK
"I will always think that David Tennant was the best Doctor, but i think Matt Smith will be good too."
Frances, 9, Oxford, UK
"He looks to young to play the Doctor. You should have pick someone famous and older."
Brendan, 8, Barry, Wales
"WOW! he looks awesome! It's going to be hard for him to fill the role after David Tennant. But I think he's going to be brilliant as the Doctor!"
Bethan, 14, Gloucester, England
"He's okay. A famous name wouldn't work because every would think of him as the original character."
Charli, 13, UK
MATT SMITH LOOKS LIKE A GOOD DR HE WILL BE BRILLIANT!
Rebecca, 9, Ely, UK
The comments below were sent to Newsround before the 11th Doctor was revealed.
"I think Tom Chambers would be brilliant as the Doctor! Everybody loved him on Strictly Come Dancing and I think he's a great actor!"
Abbie, 13, Sheffield, England
"I heard that the person who is narrating the special episode will be the new Doctor, and that is Simon Pegg. That would be good, he would bring something new to the position."
Stuart, 12, Ipswich, England
"I think Eddie Izzard would be a good Doctor as he is funny."
Eleanor-Lucy, 10, Southport, UK
"I would really like the next Doctor to be Matthew Needham. However, I do also think that John Simm or Tom Chambers would do a really good job!"
Rosie, 13, Reading, England
"First of all Zac Efron would be awful, too young. Secondly both John Simm and David Morrisey have been on the show are unlikely to become the Doctor, though there have been exceptions. Finally no action star should become the Doctor."
Cameron, 11, George Town, Cayman Island
"I think William Mosley or Ben Barnes."
Eleanor, 10, Hauxton, UK
"Douglas Henshall, he's Scottish, funny and a brilliant actor like David. I will miss him."
Amelia, 9, Hampshire, England
"I think Bill Nighy would make a cool Doctor."
Martin, 14, Dorchester, England
"I think that James McAvoy would be a great Doctor since we saw him in Narnia and Penelope"
Rebecca, 9, Whitley Bay, England
"I would love it to still be David Tennant, but as that's not possible, I think it should be either John Simm or Eddie Izzard."
Izzi, 12, Southend-on-Sea, England
"I'd love John Simm to be the next Doctor. I thought he was GREAT as the Master, but it would be awfully confusing!! x"
Kelly, 13, Manchester, England
"I think Colin Firth should be the next Doctor coz he is really funny!"
Amelia, 10, Braintree, England
"David tennant is great, but if he was to be replaced, I think Tom Chambers would do an awesome job!"
Megan, 13, Lincoln, England
"I think that someone less known should be the Doctor"
Tash, 10, Birmingham, England
"I don't think that there should be another Time Lord - David Tennant is too hard to replace!"
Ellie, 13, Brighton, England
"I think James Nesbitt would be amazing or Simon Pegg. They're both awesome and hilarious!"
Katy, 14, Lancaster, England
"Ed Petrie! That would be brilliant! Or Colin Firth."
Ellen, 11, Leicestershire, England
"I think Jason Isaacs would be good as Doctor Who"
Hermione, 11, Sidcup, England
"I don't mind as long as their good at playing the Doctor and they are not a girl. The Doctor is a male and his companion has always been female and changing that would sort of spoil it."
Hannah, 10, York, England
"I think that Johnny Depp should be the next Doctor because he is funny!"
Laura, 10, Monmouth, England
"I think there should be a female Doctor."
Francesca, 10, Watford, England
"I think that John Simm or Billie Piper should be the next Doctor. Billie Piper was great as Rose and this would give it a bit of a twist!"
Charlie, 11, Crowborough, England
"I don't really mind who the next Doctor is, as long as she or he is really funny!"
Cheyanne, 13, Bristol, England
"I don't mind, as long as it isn't somebody like Zac Efron. Ugh!"
Kate, 13, New Malden, England
"I've always thought Bill Paterson would be a good doctor. Or possibly Damian Lewis, as the 10th Doctor always said he wanted to be ginger."
Sam, 15, Colchester, England
"I think that David Morrisey would be a great Doctor after his debut in The Next Doctor. However he is Jackson Lake, so I don't think he will get the keys to the TARDIS this time. But whoever is is they'll have a life-changing experience and they'll probably be great!!!"
Ben, 11, Bournemouth, England
"I think Douglas Henshall should do it from Primeval."
Matthew, 11, Bournemouth, England
"I think James McAvoy should be the next Doctor because he is funny, good looking and Scottish just like David Tennant."
Melissa, 14, Sheffield, England
"I think James Nesbitt because he is a brilliant actor. I love him. But, David Tennant is and will always be the best Doctor on Doctor Who."
Bev, 11, Widnes, England
"I think Johnny Depp because he is so cute!!!!"
Olivia, 9, Northampton, England
"I think Paterson Joseph will be the Doctor, but I think nobody will be better than David Tennant. He is the best Doctor ever!"
Hattie, 10, Faversham, England
"I personally think Zac Efron would be a good Doctor but nobody can replace David - he's been the best Doctor by a mile!!!!"
Lesley, 14, Liverpool, England
"I think that David Tennant should stay as the Doctor as he is the best. If someone new HAS to be the new Doctor, I think it should be Richard Hammond as he is very funny and is like David Tennant in a lot of ways."
Emeline, 13, Northampton, England
"I think that John Simm will be the next Doctor as he did a good job as being the Master in series three."
Adnan, 13, Milton Keynes, England
"I don't think there should be a new Doctor Who. Everyone thinks David Tennant is the best and he knows he is, so I think he shouldn't leave and they should surprise everyone with him NOT leaving."
Beth, 12, Bury, England
"I think James Nesbitt should be the next Doctor as he is a brilliant actor and he would be even better as the new Doctor."
Maisie, 12, Lincoln, England
"I think the next Doctor should be Catherine Tate."
TJ, 11, Lancaster, England
"I think that Zac Efron would be a good Time Lord."
Ellie, 10, Fife, Scotland,
"David Tennant was and always will be the best doctor but I think it will be John Simm who plays the master."
Liam, 13, Coventry, England
Annika, 12, Edinburgh, Scotland
"I think James Nesbitt should be the next Doctor because he comes as bit of a rogue and that's just like the doctor."
Scott, 12, Hornchurch, England
"I was hoping it would be David Morrisey who was in the Christmas special but now I hope it is either; Harrison Ford, Tom Cruise or Johnny Depp. But really I don't mind. It would be good if the doctor before David Tennant came back."
Cathy, 10, Kendal, England
"No-one, David Tennant should stay!"
Sophie, 13, Eastbourne, England
"I think David Morrisey because he is a great actor!!!"
Kieran, 8, Dundee, Scotland
"I don't mind, as long as it isn't a woman! That would be strange..."
Emma, 11, Liverpool
"I really think John Simm should take over!!"
Rebecca, 11, Manchester, England
"I'd love it to be Simon Pegg as he is a talented actor."
OnlyMe, 12, Aberdeen, Scotland
"Catherine tate because she is Dr Donna."
Nathan, 12, Baar, Switzerland