Colin Baker was born in Waterloo, London, England. He moved north to Rochdale with his family when he was three years old. He was educated at St Bede's College, Manchester, and originally studied to become a solicitor. At the age of 23, Baker enrolled at the London Academy of Music and Dramatic Art (LAMDA).
One of Baker's first acting jobs, in 1970, was a supporting role in a BBC adaptation of Jean-Paul Sartre's trilogy The Roads to Freedom. In 1972 he played Anatole Kuragin in a BBC serial adaptation of War and Peace. His most prominent role in the 1970s was as the villainous Paul Merroney in The Brothers, a role that he played from 1974 to 1976. In the final episode of Fall of Eagles, Baker appeared as Crown Prince Willy of the German Empire. He also guest-starred as Bayban the Butcher in a 1980 episode of Blake's 7. In 1983 he featured in a BBC production of A.J. Cronin's The Citadel.
Baker made his first appearance in Doctor Who as Commander Maxil in the story Arc of Infinity (1983). Producer John Nathan-Turner described Baker's performance as being "quite arch" and a little sassy. Maxil was one of the few characters actually to shoot the Doctor, then played by Peter Davison.
At the time of Baker's casting as Davison's successor, he was the only actor portraying the Doctor to have appeared in the television series as another character prior to taking on the leading role (in 2013 Peter Capaldi was announced as the Twelfth Doctor after having previously appeared in another role in the 2008 episode "The Fires of Pompeii"). When Baker was cast to replace Davison, many fans cited that shooting scene in Arc of Infinity, prompting Baker to say jokingly that he got the part of the Doctor by killing the incumbent. He is no relation to Tom Baker, who previously played the Fourth Doctor in Doctor Who.
Baker's first appearance as the Doctor occurred at the final minutes of The Caves of Androzani, where he delivered his first few lines. The closing title sequence for episode four features Baker's face instead of Peter Davison and credits him as the Doctor before Davison's own credit. This was the first (and, to date, only) time that the new lead received top billing in the final story of an outgoing Doctor. Baker then made his first full story debut the following week in The Twin Dilemma. It was the first time since 1966, and only the second time in the series' history, that a new leading actor's debut story was shown before the conclusion of the previous lead's season.
Baker's era was interrupted by an 18-month hiatus which was announced in February 1985, midway through transmission of his first full season. The Controller of BBC1 at the time, Michael Grade, criticised Doctor Who, saying that the programme had become overly violent in 1985. Grade later admitted that he "hated" the series, which he described as a "very clunky studio show". One new Doctor Who story, Slipback, was produced for radio during the hiatus, which starred Baker and his regular television companion Nicola Bryant.
Doctor Who returned to television for its 23rd season in September 1986. The season featured a reduction in episodes, was made entirely on video for location scenes for the first time and was produced as a 14-episode-long serial called The Trial of a Time Lord. This serial was a meta-textual reference to the fact that the series itself was "on trial" at this time. In 1986 Baker told an interviewer, "Tom Baker did it for seven years. ... There's a part of me which likes to have a tilt at records. I would like to think that maybe I'd still be doing it in eight years' time." Later that year, Michael Grade agreed to commission another series on the condition that Baker was replaced. The BBC's Head of Series, Jonathan Powell, later said that the BBC was looking for "one last chance saloon, for an actor who would take off with the public." He was removed from the part after starring in only eleven stories and just short of three years in the series, including the hiatus, making his tenure as the Doctor the shortest at that point. After his sacking, Baker refused to return to record a regeneration sequence. Instead, his replacement, Sylvester McCoy, played the fatally injured Sixth Doctor in a blonde wig as he regenerates in the opening minutes of Time and the Rani, his face hidden by video effects as the regeneration process occurs.
On 4 September 2011 at Riverside Studios, Hammersmith, London, Baker accepted the presidency of the Doctor Who Appreciation Society, which had previously been held by Jon Pertwee and Nicholas Courtney. Baker was elected following an online poll of the society's members where he won more votes than all the other candidates combined.
From 5 June to 19 August 1989 Baker agreed to appear as the Doctor once more, in the stage play Doctor Who - The Ultimate Adventure, taking over from original lead Jon Pertwee who had fallen ill.
In 1992, Colin Baker became the first (and so far only) Doctor to write a published Doctor Who story, The Deal, as part of Doctor Who Magazine's Brief Encounters series. He wrote a second Brief Encounter the following year. Both featured the Sixth Doctor and Mel. In 1994 Baker wrote a comic strip, The Age of Chaos featuring the Sixth Doctor and Frobisher, and in 2001 contributed a story entitled "The Wings of A Butterfly" to a charity short story anthology based on Doctor Who, "Missing Pieces". He also presented special Doctor Who videotape releases Cybermen – The Early Years in 1992 and The Colin Baker Years in 1994, with the latter a look back at his tenure on the series highlighted by clips and his memories.
Baker reprised the role on television only once after his official run ended, in the 1993 Children in Need charity special Dimensions in Time alongside Jon Pertwee, Tom Baker, Peter Davison and Sylvester McCoy.
In 1997 Baker provided audio dialogue for the BBC video game Doctor Who: Destiny of the Doctors.
1999 saw Baker voice his first Doctor Who audio adventure for Big Finish Productions, The Sirens of Time. As of June 2014 Baker has recorded 83 Sixth Doctor audio plays with more planned for future release. These audio plays are generally well received by fans and in a poll conducted by Doctor Who Magazine, Baker was voted the "greatest" of the Doctors in this format.
In recent years, Baker has appeared on a number of DVD releases of his episodes, featuring in either "making-of" documentaries or commentaries. The documentary Trials and Tribulations, included in the 2008 DVD release of The Trial of a Time Lord examines his turbulent three years on the show.
In November 2013 Baker co-starred in the one-off 50th anniversary comedy homage The Five(ish) Doctors Reboot.
Since leaving Doctor Who Baker has spent much of his time on the stage with appearances throughout the country in plays as diverse as Peter Nichols' Privates on Parade, Ira Levine's Deathtrap, Ray Cooney's Run for Your Wife and Ariel Dorfman's Death and the Maiden. For many years he has been a pantomime stalwart. In 2000 he appeared in Snow White and the Seven Dwarfs alongside actress Louise Jameson who had previously played the Fourth Doctor's companion Leela. In 2003 he starred in the Carl Rosa Opera Company's production of operetta H.M.S. Pinafore, directed by Timothy West. In 2008, he toured with ex-wife Liza Goddard in She Stoops To Conquer. More recent theatre appearances have seen Baker tackle the role of Inspector Morse in House of Ghosts and a UK tour of The Woman in White.
In 1991 Baker played a Doctor-like character in the BBV video series The Stranger. This character appeared in six video adventures as well four audio stories. Another standalone BBV drama entitled The Airzone Solution appeared in 1993 and featured former Doctor Who actors Jon Pertwee, Peter Davison and Sylvester McCoy.
Television work during the 1990s included guest appearances in the BBC's medical drama Casualty, The Knock, Dangerfield, the first episode of Jonathan Creek, Channel 4's adaptation of A Dance to the Music of Time and as himself as the resident celebrity in 'Dictionary Corner' on the daytime quiz show Countdown, also on Channel 4.
In 2003 Baker appeared on Top Gear, participating on a one-lap run on the Top Gear track in a Honda Civic hatchback. Baker competed against a Klingon, a Cyberman, a Dalek, Darth Vader and Ming the Merciless. Baker came in 4th position, with the Cyberman coming 1st.
A 2005 guest appearance in comedy sketch show Little Britain was never transmitted but can be seen in the deleted scenes special feature on the Little Britain series 3 DVD. Other television appearances have seen Baker appear in Kingdom, Hustle and Doctors.
Away from his Doctor Who work for Big Finish Productions (see above), Baker appeared in the audio dramas Sapphire and Steel: The Mystery of the Missing Hour and the 3 part Earthsearch Mindwarp. The latter, based on a James Follett novel, was broadcast on the digital radio station BBC 7 in 2006.
In 2010, Baker narrated and provided additional voices for Candy Jar Books' comedy sci-fi audiobook Kangazang, written by Terry Cooper.
Baker's film work over the years includes The Harpist (1999), The Asylum (2000) and D'Artagnan et les trois mousquetaires (2005). In 2010 he filmed scenes for an independent feature film, Shadows of a Stranger. Since 1995 Baker has written a regular weekly column for local newspaper Bucks Free Press. A compilation of his articles from 1995 to 2009 were published in the book, Look Who's Talking.
On 7 November 2012, it was confirmed that Baker would be participating in the 12th series of I'm a Celebrity...Get Me Out of Here! Baker finished in 8th place out of 12 celebrities, losing out to Eric Bristow.
Baker's first wife was actress Liza Goddard who had appeared with him in the TV series The Brothers. Their marriage lasted 18 months and ended in divorce. With his second wife, actress Marion Wyatt, Baker has four daughters. They also had a son who died of sudden infant death syndrome. Baker is a friend of American writer Stephen R. Donaldson, who dedicated his 1991 novel Forbidden Knowledge to him.
Baker is a critic of fox hunting and was among more than 20 high-profile people who signed a letter to members of parliament in 2015 to oppose Conservative prime minister David Cameron's plan to amend the Hunting Act 2004.Look Who's Talking (Hirst Books), First Published December 2009. First reprint February 2010 ISBN 978-0-9557149-2-4
Second Thoughts (Hirst Books), First Published September 2010 ISBN 978-0-9566417-6-2
Gallimaufry: A Collection of Short Stories. Hirst Publishing. 30 September 2011. ISBN 1-907959-02-5.
Sixth Sense – from the columns of the Bucks Free Press. FBS Publishing Ltd. 6 April 2017. ISBN 978-0993204371