1980

February

 * 14 - Dr. Owen Harper, Torchwood Three operative, was born. (TW: Exit Wounds, WEB: torchwood.co.uk)

April

 * 15 - Samantha Jones, future companion of the Eighth Doctor, was born. (EDA: Unnatural History)

December

 * 8 - Knowing of the impending assassination of former member of The Beatles John Lennon, the Seventh Doctor, Ace and Bernice Summerfield travelled to New York City. Mark David Chapman, influenced by the Blue, shot and killed him anyway. (NA: The Left-Handed Hummingbird)
 * 25 - Professor Edward Travers, CBE, died. (MA: Downtime)

Unknown dates

 * Victoria Waterfield visited Det-Sen Monastery in Tibet, believing she was following a summons from her father. (MA: Downtime)
 * Sarah Jane Smith claimed to Laurence Scarman that she had come from the year 1980. (DW: Pyramids of Mars; see UNIT dating controversy).

Negated timeline

 * The Fourth Doctor took Sarah Jane Smith and Laurence Scarman from 1911 and showed them what 1980 would look like if Sutekh had succeeded in freeing himself; a lifeless Earth orbiting a dead sun. This example of alternate time convinced Sarah that they had to return to 1911 and stop Sutekh. (DW: Pyramids of Mars)

January

 * 5 - DW: The Horns of Nimon Part 3 was first broadcast.
 * 12 - DW: The Horns of Nimon Part 4 was first broadcast, bringing an end to the season six weeks earlier than planned due to the cancellation of DW: Shada. This was the final story to feature the original 1960s arrangement by Delia Derbyshire of the Doctor Who theme music, specifically the arrangement introduced in the 1967 serial DW: The Macra Terror. This was also the final use of the diamond-shaped series logo and Bernard Lodge "tunnel" opening sequence. This story also brought to a close Graham Williams' involvement as producer and of Douglas Adams as a member of the writing team. Also, this was David Brierley's final televised performance as the voice of K9 (although he also voiced the character for the incomplete Shada).
 * 24 DWN: Doctor Who and the Underworld was first published.
 * The American edition of DWN: Doctor Who and the Android Invasion was published by Pinnacle Books.

February

 * 4 - Former Script Editor and writer David Whitaker died in Australia.
 * 21 - DWN: Doctor Who and the Invasion of Time was first published.

March

 * 20 - DWN: Doctor Who and the Stones of Blood was first published.
 * Target Books reissued the 1976 non-fiction book REF: The Making of Doctor Who.
 * The American edition of DWN: Doctor Who and the Seeds of Doom was published by Pinnacle Books. This was the last re-print of a Doctor Who novelisation by Pinnacle, and as of 2009 stands as the last American edition of a Doctor Who novel to date.

April

 * 24 - DWN: Doctor Who and the Androids of Tara was first published.

May

 * 26 - DWN: Doctor Who and the Power of Kroll was first published.

June

 * The BBC announced that K9 would be leaving Doctor Who during the next season. According to The Television Companion by David J. Howe and Stephen James Walker, the response to this announcement by fans inspired John Nathan-Turner to pitch the idea of a spin-off series featuring the character, which later became K9 and Company.
 * 4 - Philip Olivier was born.
 * 26 - DWN: Doctor Who and the Armageddon Factor was first published. Due to the inability of Target Books to come to an agreement with Douglas Adams, this would ultimately be the last of the Key to Time- arc serials to be novelised. The remaining serial, DW: The Pirate Planet, would not be officially novelised.
 * DWN: Junior Doctor Who and the Brain of Morbius was first published. This was a short version of DWN: Doctor Who and the Brain of Morbius and was the second of two such books released (a paperback edition of DWN: Junior Doctor Who and the Giant Robot was also released in 1980). Reportedly the book was originally to have been released in 1978.
 * Doctor Who Magazine began publishing Doctor Who-universe comics written by future comics superstar writer Alan Moore.

August

 * Doctor Who Annual 1981 was published. Beginning this year the annual, previously published each September, moved to August.
 * 6 - Barry Justice (King Charles IX in DW: The Massacre of St Bartholomew's Eve) died in London.
 * 7 - The final issue of Doctor Who Weekly was published; it changed to a monthly magazine in September.
 * 21 - DWN: Doctor Who and the Keys of Marinus and DWN: Doctor Who and the Nightmare of Eden were first published. For the first time in several years, Target Books released more than one book on the same day.
 * 30 - DW: The Leisure Hive Episode 1 was first broadcast, launching a longer-than-usual Season 18 that was Tom Baker's final season and the first series produced by John Nathan-Turner. Among the numerous changes evident with this episode was the introduction of a radically different arrangement of the Doctor Who theme by Peter Howell and a new neon-tubing style series logo. A modified costume was also introduced for the Doctor. Season 18 would be the last truly "season-long" series, as during the Davison era the show would air from January to March only (two episodes per week), and be subject to an ever-decreasing number of episodes thereafter.

September

 * Doctor Who Magazine began publishing as a monthly publication, initially changing its title from Doctor Who Weekly to Doctor Who: A Marvel Monthly.
 * John Nathan-Turner approached Peter Davison about taking over from Tom Baker as the star of Doctor Who.
 * 6 - DW: The Leisure Hive Part 2 was first broadcast.
 * 13 - DW: The Leisure Hive Part 3 was first broadcast.
 * 20 - DW: The Leisure Hive Part 4 was first broadcast.
 * 27 - DW: Meglos Part 1 was first broadcast, featuring the return of Jacqueline Hill to Doctor Who, albeit as another character. John Leeson returned as the voice of K9.

October

 * 4 - DW: Meglos Part 2 was first broadcast.
 * 11 - DW: Meglos Part 3 was first broadcast.
 * 16 - DWN: Doctor Who and the Horns of Nimon was first published. (Although the series branding changed to a new logo, the the previous logo was still used by Target Books for several more volumes.
 * 18 - DW: Meglos Part 4 was first broadcast.
 * 24 - At a press conference, the BBC announced that Tom Baker would be leaving Doctor Who at the end of the current season.
 * 25 - DW: Full Circle Episode 1 was first broadcast, launching what would become known as the E-Space Trilogy. Matthew Waterhouse debuted as new companion Adric.

November

 * The BBC announced that Peter Davison was cast as the Fifth Doctor.
 * REF: A Day with a TV Producer, a non-fiction work profiling John Nathan-Turner and the production of DW: The Leisure Hive, was published.
 * 1 - DW: Full Circle Part 2 was first broadcast.
 * 8 - DW: Full Circle Part 3 was first broadcast.
 * 13 - DWN: Junior Doctor Who and the Brain of Morbius was published in paperback.
 * 15 - DW: Full Circle Part 4 was first broadcast.
 * 22 - DW: State of Decay Part 1 was first broadcast.
 * 29 - DW: State of Decay Part 2 was first broadcast.

December

 * 4 - DWN: Doctor Who and the Monster of Peladon was first published.
 * 6 - DW: State of Decay Part 3 was first broadcast.
 * 8 - Ex-Beatle John Lennon, who appeared as himself in DW: The Chase, was shot and killed by Mark David Chapman outside his home in New York City.
 * 13 - DW: State of Decay Part 4 was first broadcast.
 * 30 - Tom Baker and Lalla Ward married; Baker was in the midst of filming DW: The Keeper of Traken, while Ward's final episodes as Romana had not yet been broadcast.
 * Marvel Premiere issue 57 was published by Marvel Comics in the United States. This comic, featuring Fourth Doctor comic strip reprints from Doctor Who Weekly, was the first American comic ever published based upon the Doctor Who TV series (a previous comic published in the mid-60s by another US publisher was based upon the Dr. Who and the Daleks movie, not the TV series). This comic, and three other issues that follow, led to the launching of a monthly Doctor Who title by Marvel in 1984.

Unknown dates

 * The Adventures of K9, a children's book series by David Martin, was published by Sparrow Books.
 * Tom Baker and Lalla Ward appeared as the Fourth Doctor and Romana in a series of commercials for Australian television, advertising Prime Computers (a room-sized computer system for business). While most of the commercials featured them in their standard character roles, the final commercial in the series had Romana flirting with the Doctor and ended with the Doctor proposing marriage to her.