1986 (releases)


 * 1 January - Actor Colin Morgan was born.
 * 9 January - Doctor Who - The Gunfighters was first published.
 * 2 February - Actor Donald Eccles died.
 * 13 February - Doctor Who - The Time Monster was first published.
 * 16 February - Narrator Howard Da Silva died.
 * 13 March - Doctor Who - The Twin Dilemma was first published.
 * 10 April - Doctor Who - Galaxy Four was first published.
 * 27 April - Actor Jenna-Louise Coleman was born.
 * 14 May - Actor William Lindsay died.
 * 15 May - Doctor Who - Timelash was first published.
 * 15 - Turlough and the Earthlink Dilemma was first published. Turlough and the Earthlink Dilemma was the first release of a planned spin-off series of original novels called "The Companions of Doctor Who". As such, this book was the first original novel based upon characters from the TV series (discounting shorter works released in annuals).
 * 15 - REF: Doctor Who: The Early Years was first published.
 * 24 May - Writer Robert Holmes died. His last work was Part 13 of The Trial of a Time Lord, aka Part 1 of The Ultimate Foe.
 * Around the time of Holmes' death, Eric Saward resigned as script editor due to a disagreement with John Nathan-Turner over Saward and Holmes' plans for the final part of the Trial story arc; Nathan-Turner commissioned Pip and Jane Baker to write the final chapter.
 * 31 May - Actor Sylvia Coleridge died.
 * Severn House launched Make Your Own Adventure with Doctor Who, a series of "interactive" books in which readers made decisions every few pages that directed the storyline. The first two books published were Search for the Doctor and Crisis in Space. Later in the year, US publisher Ballantine reissued the books (in different order) under its Find Your Fate line.
 * 11 June - Actor Reed De Rouen died.
 * 12 June - Doctor Who - The Mark of the Rani was first published.
 * 23 June - Actor Nigel Stock died.
 * 23 - Actor Willis Chung was born.
 * 10 July - Doctor Who - The King's Demons was first published.
 * 17 July - REF: Travel Without the TARDIS was first published.
 * Garden of Evil and Race Against Time, books three and four of the Make Your Own Adventure with Doctor Who line, were first published.
 * 14 August - Production concluded on the fourteen-part The Trial of a Time Lord. Unknown to most at the time, this concluded Colin Baker's involvement with the series.
 * 21 August - Doctor Who - Slipback was first published. Adapted from the radio play of the same name, this was the first novelisation of a Doctor Who story not produced for television. (Note: REF: Howe's Transcendental Toybox says 14th August release.)
 * 22 August - REF: Doctor Who - Special Effects was first published.
 * Marvel Comics in the United States published the 23rd and final issue of Doctor Who, a monthly series of reprints of comic strips and other material from Doctor Who Magazine. Discounting distribution of imported works from the UK published by Marvel UK and, later, Panini, the next Doctor Who comics published specifically for the American market did not appear until IDW Publishing began its own series of DWM reprints and original works in 2007.
 * 6 September - The Mysterious Planet Part 1 (aka The Trial of a Time Lord Part 1) debuted on BBC1, launching the belated Season 23. The series returned to its original twenty-five-minute eipsode format and the number of episodes per season was increased from thirteen to fourteen. However, given the actual episode length reverted back to twenty-five minutes, this resulted in a considerably shortened season compared to the 1984 and previous seasons. The Trial of a Time Lord, although not the first season to consist of a single story arc (see The Key to Time), was the first time only one on-screen title was used for an entire season, although the fanbase and producers divided the tale into four stories. A new arrangement of the theme music, by Dominic Glynn, was introduced. Lynda Bellingham, as the Inquisitor, and Michael Jayston, as the Valeyard, were introduced and became regulars for this season. Sabalom Glitz was introduced. This was the first fall debut for a new season of Doctor Who since 1980.
 * 11 September - Doctor Who - The Savages was first published.
 * 11 - Harry Sullivan's War was first published. This was the second of three released under the Companions of Doctor Who spin-off line. It was written by Ian Marter, who had portrayed Harry Sullivan in the TV series more than a decade earlier. Marter died a few weeks later, making this the final book released (but not the final book written) in his lifetime.
 * 13 September - The Mysterious Planet Part 2 (aka The Trial of a Time Lord Part 2) debuted on BBC1.
 * 15 September - Actor Christian Cooke was born.
 * 18 September - REF: The Doctor Who File was first published.
 * 20 September - The Mysterious Planet Part 3 (aka The Trial of a Time Lord Part 3) debuted on BBC1.
 * 20 - Writer and script editor Dennis Spooner died.
 * 27 September - The Mysterious Planet Part 4 (aka The Trial of a Time Lord Part 4) debuted on BBC1.
 * 28 September - Actor Denis Carey died.
 * 29 September - Doctor Who Collected Comics, a reprinting of several Doctor Who Magazine strips, was published by Marvel Comics.
 * Mission to Venus and Invasion of the Ormazoids, books five and six of the Make Your Own Adventure with Doctor Who line, were first published. Severn House discontinued the line after these books.
 * According to The Television Companion by Howe and Walker, at some point this month, Colin Baker was informed that his contract to play the Doctor was not being renewed.
 * 4 October - Mindwarp Part 1 (aka The Trial of a Time Lord Part 5) debuted on BBC1.
 * 6 October - Around this time, BBC Controller Michael Grade approached the originator of Doctor Who, Sydney Newman, for ideas on how to revvitalise Doctor Who. In a letter dated 6th October, Newman provided some ideas and suggested he be brought on board as executive producer of the series. He also attempted to be credited as the show's creator. Subsequent meetings, however, failed to result in Newman's return to direct involvement in the series.
 * 8 October - Actor Michael Obiora was born.
 * 11 October - Mindwarp Part 2 (aka The Trial of a Time Lord Part 6) debuted on BBC1.
 * 16 October - Doctor Who - Fury from the Deep was first published. It was promoted as a "bumper volume" due to a higher word count than most Target Books released up to this time.
 * 18 October - Mindwarp Part 3 (aka The Trial of a Time Lord Part 7) debuted on BBC1.
 * 25 October - Mindwarp Part 4 (aka The Trial of a Time Lord Part 8) debuted on BBC1. Nicola Bryant left the series with this episode.
 * 28 October - Actor and writer Ian Marter died from a diabetes-related heart attack in London on his 42nd birthday. He left behind several Target manuscripts which were published posthumously over the next couple of years.
 * REF: Doctor Who: The Companions was first published.
 * 1 November - Terror of the Vervoids Part 1 (aka The Trial of a Time Lord Part 9) debuted on BBC1. This was the debut of Bonnie Langford as Melanie Bush. Mel became the first companion (aside from his inaugural companion Susan) whose first meeting with the Doctor was never chronicled on television. Honor Blackman, who starred in the Sydney Newman-created The Avengers, guest starred.
 * 8 November - Terror of the Vervoids Part 2 (aka The Trial of a Time Lord Part 10) debuted on BBC1.
 * 11 November - REF: The Doctor Who Cookbook was published in paperback.
 * 15 November - Terror of the Vervoids Part 3 (aka The Trial of a Time Lord Part 11) debuted on BBC1.
 * 20 November - Doctor Who - The Celestial Toymaker was first published.
 * 22 November - Terror of the Vervoids Part 4 (aka The Trial of a Time Lord Part 12) debuted on BBC1.
 * 29 November - The Ultimate Foe Part 1 (aka The Trial of a Time Lord Part 13) debuted on BBC1. This was the final episode to carry a writer credit for the late Robert Holmes, and was also the last to credit Eric Saward as script editor.
 * The US edition of REF: Doctor Who: The Companions was first published.
 * 4 December - Doctor Who - The Seeds of Death was first published.
 * 6 December - The Ultimate Foe Part 2 (aka The Trial of a Time Lord Part 14) debuted on BBC1, concluding Season 23. Although not widely known at the time, this was Colin Baker's final appearance in the series. This also marked the final use of Dominic Glynn's short-lived theme arrangement and the neon-tubing series logo that had been in place (with adjustments upon Baker's arrival) since 1980. Lynda Bellingham and Michael Jayston, having spent the full season as regular cast members, took their leave.
 * The BBC announced that Colin Baker would not be returning as the Doctor in the next series.
 * 14 December - Actor Dermot Tuohy died.
 * 26 December - Actor Leslie Dwyer died.