A lot of people are turning up at the blog seeking an answer to this question.
The answer, as far as I know, is that he is not. But many others from the Doctor Who universe are - including several of yer actual Doctors. Don't look for Moffat or RTD though - or Matt Smith for that matter - they ain't there. Neither are any of the modern Doctors, despite frequent claims to the contrary. The best of the fake accounts was a Chris Eccleston one, easily spotted by virtue of the fact that he seemed very jolly and affable.
I follow quite a few of them - including Nicola Bryant who sadly hasn't posted any more pictures of her leather-bra'd breasts recently - and it's quite affecting to see the Doctor Who Family being mates on Twitter. Very nice indeed. It's not very nice to see some at each others' throats, but it is often funny.
Anyway I've compiled a list below of some types you might want to follow. And, just for the record, Matt Smith isn't on Twitter. And neither is David Tennant, nor Peter Capaldi. I would bet my Perigosto Stick you won't see Eccleston tweeting away anytime soon either...
Doctor Who types on Twitter
Most obvious of all, The Doctors.
Doctors on Twitter
— Peter Davison (@PeterDavison5) September 19, 2012
• Paul McGann - Who's Lazenby, the Eight Doctor
• John Hurt - The Ninth-ish Doctor; don't expect to hear him in Big Finish
• The Five(ish) Doctors - Kickstarted a Twitter frenzy; think it's done by Davison
Doctor Who Companions on Twitter
Most of the existing companions have taken the plunge...
• Nicola Bryant - Still the chestiest companion of all and a darling on Twitter. Saucy too
• Billie Piper - Wose herself
• Yee Jee Tso - Chang Lee, The Asian Child
• Freema Agyeman - Beautiful Freema Agyeman, aka Martha hmm-this-isn't-working-out Jones
Tough job someone has to do it x pic.twitter.com/RtORvnTKOI
— Louise Jameson (@Lou_Jameson) June 16, 2013
• Janet Fielding - Janet Fielding, aka Tegan Jovanka, still terrifying
• Karen Gillan - Ginger, straight, round-faced Amy Pond
• Louise Jameson - Leela. Still kills people with janus thorns occasionally
• Anneke Wills - Played Polly Lopez, married Michael Gough, seems to have led a life
1st pic of Matt and I in character was released 4 yrs ago today, but, I have the real one..from the 1st camera test pic.twitter.com/72ldPCvpM3
— Karen Gillan (@KarenGillan2) February 18, 2014
• Katy Manning - Who is Katy Manning? Depends who you ask and which men you mean. AKA Jo Grant
• Sophie Aldred - Ace McShane; posh, streetwise Londoner; white kid
• Frazer Hines - Jamie's Awae in his Twitter stream. AKA Frazer Hines who, weirdly, sounds like one os the least Scottish people ever. Played Jamie McCrimmon
• Arthur Darvill - Arthur Darvill, the one who played Rory Williams
— Nicola Bryant (@thenicolabryant) March 8, 2014
• Daphne Ashbrook - Amazing Grace; McGann's first companion
• India Fisher - Sexy-voiced, jolly-hockeysticks-esqe Big Finish companion
• Bonnie Langford - Ginger, shrill, probably about as boring as they come
• Noel Clarke - Micky the Idiot, the tin dog and a massive kick-off on Twitter. Posts great Who selfies though
Doctor Who Writers on Twitter
New series writers, old series writers, NA writers, BBC Books writers, Big Finish writers, comic strip writers, comics writers, DWM writers...
• Joe Lidster - Once took ecstasy and wrote a Doctor Who story about it
• Paul Cornell - Wrote some very good novels (and a few duffers) and some middling TV episodes. Once upon a time was Who's Great White Hope; mainly does comics these days
• Eddie Robson - One of Big Finish's best writers
• Mark Morris - Horror novelist, wrote a couple of Who novels, once saw him on a panel with Ramsey Campbell
• Nick Pegg - One of the most able writers/performers/directors from the Big Finish stable; also wrote that UKIP Weather Forecast thing
• James Moran - Think he wrote some Torchwoods
• Neil Gaiman - Wrote Neverwhere and Sandman; plus The Doctor's Wife and Nightmare In Silver
• Jason Arnopp - Writes good articles in DWM; also does some horror stuff
— Mark Gatiss (@Markgatiss) November 23, 2013
• Chris Chibnall - Responsible for some of the worst new series Ws and some of the worst television ever on Torchwood; also wrote the universally lauded Broadchurch
• Ben Aaronovitch - Wrote the story that rekindled my interest in Doctor Who (Remembrance), also the Best New Adventure (The Also People); now a successful novelist in his own right
• Mark Gatiss - Should still adapt Nightshade
• Simon Guerrier - Wrote some BBC novels and BF plays; not sure I've come across any
• Cavan Scott - Co-wrote a load of action-y Big Finish plays
• Rob Shearman - Doctor Who's very own Harper Lee; wrote Dalek and most of the best Big Finish plays
• John Dorney - Big Finish?
• Andrew Smith - Wrote Full Circle; became a policeman
• Andrew Cartmel - Comes out with a lot of total tosh but wrote three bloody good New Adventures
• Christopher H Bidmead - A seeming pompous parody of himself and virtually indefensible, despite the fact I rate Castrovala, Logopolis and Frontios
• Alan Barnes - Quite enjoyed his tenure as DWM editor; didn't enjoy his Big Finish stories
Me with the legend and lovely man that is Matt Smith. pic.twitter.com/03xsUO3TRK
— Gareth Roberts (@OldRoberts953) December 24, 2013
• Gareth Roberts - Destined never to write anything not described as 'whimsical'
• Keith Temple - Wrote Planet of the Ood, which I quite liked. Recently saw it dismissed by RTD as 'macho'
• Nick Briggs - Writer of the ten-part Chumbly Empire, probably
• Justin Richards - Wrote some very good New Adventures, before his career went a little Target-era Terrance Dicks
• Phil Ford - Water of Mars, I think
• Jonny Morris - Writes well-received books and plays - plus a lot of pretty average list features for DMW
• Rebecca Levene - Edited the New Adventures for what was arguably their most successful run. Also wrote some painful New Series reviews when DWM was toeing the party line
• Lee Sullivan - Drawer of striking Doctor Who comic art - and the Love and War cover IIRC. Let's hope he got an ex gratia payment of fifty quid from the BBC for his part in creating that iconic character
• Stephen James Walker - One of the holy trinity of 90s Doctor Who cataloguers
• Mark Clapham - BBC Books alumnus; writing other things these days
• Jim Mortimore - Responsible for some of the bleakest Doctor Who writing ever - I always rated his books though. Seems to have erased himself from Doctor Who
• John Freeman - DWM editor a long time ago
• Adrian Salmon - Excellent Doctor Who artist
• Richard Bignell - One of the original Time Team members, also does the Nothing At The End of the Lane website on Doctor Who locations
• Lawrence Miles - Once the best new Doctor Who writer on the block; subsequently written lots of interesting but lengthy tracts on the show and alienated most of the people who might have employed him. GUsuallyenerally interesting though.
• Richard Marson - Wrote the JN-T book and looked a little disingenuous in subsequent interviews when claiming to be surprised at front page leads featuring Colin Baker next to the words SEX SCANDAL, used to be producer on Blue Peter
• Daniel Blythe - Another New Adventures writer who's diversified
• Moray Laing - Does the magazine that's aimed at kiddies (there's a joke there)
• Dan Abnett - Just zis guy, you know?
• Graham Kibble-White - Finally injecting some gumption into DWM reviews
Doctor Who Actors on Twitter
Actors who've been in the series; some more iconic than others...
• Tracey Ann Obermann - Cried an oil tear as a Cyberman in one of the worst scenes of all time
• Sheridan Smith - Saucy actress, McGann's Radio 7 companion
• Simon Fisher-Becker - Fat, blue, decapitated bloke
• Warwick Davies - About the only good thing from Nightmare In Silver
• Trevor Spaul - In Revelation of the Daleks and that shit Cyberman episode form the new series
• Lynda Bellingham - The Inquisitor. Loves gravy.
• Dan StarkeyDiminutive Sontaran Strax. Once saw him in a production of The 39 Steps. He was good.
Happy Christmas one and all! pic.twitter.com/tqPvYNnmf7
— Dan Starkey (@StanDarkley) December 25, 2013
• Terry Molloy - He's in the Archers and was the very sibilant Davros. Controversially I think he's the best.
• Toby Longworth - Sonorous voice. Tells of Ronnie Corbett for doing coke in that episode of Extras
• Brian Blessed - Shouty loony Ycranos in Mindwarp. Sadly never took on Blake's 7's David Jackson in an on-screen fight.
• Simon Pegg - Tufty-haired Hollywooder, oddly not included his narration of Doctor Who Confidential on Twitter bio
Special thanks to my 'Baddie' compadre in Chicago.... Michael Jayston! pic.twitter.com/mSlO5M3dnj
— Terry Molloy (@tuckerspatch) December 5, 2013
• Ian Cullen - He was in The Azetcs and hasn't stopped acting since, it would seem
• Neve McIntosh - Sexy Sapphic Silurian
• Tom Chadbon - Amniotic fluid... You, Duggan
• Anthony Head - Bat thing and Buffy bloke
• Catrin Stewart - Jenny out of the Paternoster Gang. Lower your erect Sonic.
• Jessica Martin - Mags in Greatest Show in the Galaxy; lives in the UK, not the planet Vulpana
Doctor Who Crew on Twitter
Composers, directors, production types...
• Mark Ayres - Radiophonic Workshop torch-bearer, also wrote scores for Ghost Light and Fenric, therefore brilliant
• Peter Howell - Loads of good scores from the 80s; wrote the theme tune that covers Tom, Peter and Colin's titles
What kind of slag-muffin leaves the house with this much chest on show? http://t.co/JlJcO3su
— Murray Gold (@murraygold) November 21, 2011
• Dominic Glynn - He wrote that score for Survival, and is therefore brilliant. He also wrote the Trial of a Time Lord theme tune
• Radiophonic Workshop - The Radiophonic Workshop lives again
• Murray Gold - Writes all the music for the new series. Not brilliant.
• Euros Lyn - Directed some of the more visually interesting early episodes
• Caro Skinner - Seemingly erased from Doctor Who - and Twitter - since early 2013
• Restoration Team - Official news feed; responsible for making old episodes less atmospheric for two decades; probably denying knowledge of missing episodes forever
• Ben Wheatley - I didn't really get A Field In ENgland but I'm expecting great things from his episode
• Nick Hurran - Directed that episode with the thing in it and, and the Doctor did a thing with the sonic. Yknow, that one.
• Saul Metzstein - Same. Possibly did the Wild West one
• Paul Murphy - Another director. You've heard of Wikipedia right?
Doctor Who websites, shops etc
Official streams, DWM, DWAS, shops, publishers and fora
• BBC Doctor Who - Gushing official tweets
• Doctor Who News - Gushing unofficial tweets
• The Who Shop - Sells gushing merch
• Gallifrey One - Forums full of gushing
• Wife In Space - Wonderful blog from Neil Perryman and his wife, a not-we, watching Doctor Who in order. Very little gushing
— Big Finish (@bigfinish) February 21, 2014
• Big Finish - Gushing tweets about Big Finish plays
• DWM - Gushing Panini-published tweets
• BBC Books - Gushing official book-based tweets
• DWAS - Irrelevant gush
• Telos Publishing - Novellas and thoughtful Who books
• Blogtor Who - Big Who Blog
• Silva Screen - Still publishing soundtracks after all these years
• Den of Geek - Writer of lists, repeater of rumours
• The BFI - TV and film archivists and showers
• Doctor Who Online - Big site dedicated to Whoish things
Professional fans, relatives, hangers-on, groups and unclassifiable.
• Tom Spilsbury - DWM's current 'Everything is brilliant and silly and lovely' editor
• David J Howe - Has a transcendental toybox
• Ed Stradling - Testy video guy
• Mitch Benn - often funny songsmith, used to be a testy presence on Gallifrey One
• Toby Hadoke - Moths ate his Doctor Who scarf
• Sean Pertwee - Jon's son. Best avatar on Twitter ever
• Sue Vertue - Moff's missus. Responsible for Sherlock, therefore lack of regular Who, depending on who you listen to
• Edward Russell - Doctor Who brand manager? Apparently spends a lot of time talking about his band
— Matthew Sweet (@DrMatthewSweet) October 25, 2013
• Clayton Hickman - Former DWM editor, possibly gone back to graphic design
• Gary Gillatt - Former DWM editor; now writes affected reviews in DWM
• Barnaby Edwards - Um, writer? Something Big Finishy
• Ben Cook - Seemingly the only person who wrote anything in DWM for many, many yeas. Now has red hair.
• Jason Haigh-Ellery - One of the Big Finish lot
• Jon Culshaw - Does Tom Baker impressions
• Gary Russell - Former DWM editor, script editor, always been a bad writer
• Matthew Sweet - Seemingly on a mission to paint himself as the thinking man's Doctor Who reviewer. Has a doctorate and is frequently credited as Doctor Matthew Sweet, which would sound like a Who villain if you removed his christian name
— TheFishDr (@dayoftheFishDr) November 24, 2013
• Nev Fountain - Dead Ringers fella, has written some odd Big Finish things; incredibly having sex with Nicola Bryant
• Philip Morris - Basically you owe this man a pint
• Paul Vanezis - Restorerer
• Ian Levine - On a daily mission to erase every scrap of goodwill due for retrieving lots of 60s episodes from a skip
• Michael Troughton - Pat's son, wrote a book on his Dad
• Steve Roberts - Professional missing episodes rumour refuter; Restoration Team alumnus
— Jeff Parker (@Parkerslounge) July 7, 2013
• Patrick Mulkern - Radio Times writer, not always on-message
• Hyde Fundraisers - Money-raising fancy-dress legends. Responsible for making Davros says the words "I was in York this weekend," to Colin Baker
• Peter Crocker - Another Restoration Team member
• James Goss - Former BBCi fella responsible for Scream of the Shalka and the like. Got a bit of a rough ride in a recent 2005 retrospective in DWM
• Jeff Parker - Doctor Who Experience guy
Feel free to suggest any I've missed.