1978

March

 * 8 - The first Part of a radio play by Douglas Adams entitled The Hitchhiker's Guide to the Galaxy airs on BBC Radio, launching an entertainment franchise that would in the coming decades include novels, sequel radio plays, a TV series and a movie. The Doctor was a fan of this series and referenced it on several occasions. (DW: Ghost Light, The Christmas Invasion)

December

 * At St. Benedict's School in Perivale, Chad Boyle almost hits Dorothy McShane with a brick, but was stopped by an adult Ace. (NA: Timewyrm: Revelation)
 * In an alternate timeline, Chad Boyle hits Dorothy McShane in the head with a brick, killing her. The Timewyrm recruits him in her battle against the Doctor and Ace. (NA: Timewyrm: Revelation) Although the novel dates this as 1976, this happens when Dorothy was eight years old (she was born in 1970).

Unknown dates

 * The Doctor and Romana searched for the third segment of the Key to Time on Earth, encountering the Ogri. (DW: The Stones of Blood)
 * Chris Parsons graduates from Cambridge and soon begins his post-graduate studied at St. Cedd's College. (DW: Shada)
 * The Doctor shipped the newly built K-9 Mark III to Lavinia Smith's home in South Croydon as a gift for Sarah Jane Smith. However, the gift was not received by her until the 18th December 1981. (KAC: A Girl's Best Friend)
 * The Doctor brings Anji Kapoor and Fritter to a Hollywood bar, where they meet special effects photographer Ron von Arnim and later Noël Coward, who has arrived here from the 1960s using pinking shears given him by Iris Wildthyme which could cut through the fabric of space and time. (EDA: Mad Dogs and Englishmen)

January

 * 2 - Debut of Blake's 7 on the BBC. Created by Terry Nation, the series has many connections to Doctor Who both behind and in front of the camera.
 * 7 - DW: Underworld Part 1 was first broadcast.
 * 8 - Debut of All Creatures Great and Small on UK television. The series co-stars Peter Davison and launches him to stardom, leading to his being cast as the Fifth Doctor a few years later.
 * 14 - DW: Underworld Part 2 was first broadcast.
 * 19 - DWN: Doctor Who and the Face of Evil was first published.
 * 21 - DW: Underworld Part 3 was first broadcast.
 * 25 - Fred Ferris, who played the part of Bert Rowse in DW: Planet of Giants, died.
 * 28 - DW: Underworld Part 4 was first broadcast.

February

 * The punk rock group The Art Attacks releases the single "I Am a Dalek" on Albatross Records.
 * 4 - DW: The Invasion of Time Part 1 was first broadcast.
 * 11 - DW: The Invasion of Time Part 2 was first broadcast.
 * 16 - Doctor Who Discovers: The Conquerors was first published.
 * 18 - DW: The Invasion of Time Part 3 was first broadcast.
 * 25 - DW: The Invasion of Time Part 4 was first broadcast.

March

 * 4 - DW: The Invasion of Time Part 5 was first broadcast.
 * 11 - DW: The Invasion of Time Part 6 was first broadcast, concluding Season 15. Louise Jameson leaves the series with this Part. Also final appearance of K-9 Mark I until the K-9 spinoff TV series of 2009.
 * 30 - DWN: Doctor Who and the Horror of Fang Rock was first published.

April

 * 20 - Doctor Who Discovers: Strange and Mysterious Creatures was first published. Although the Doctor Who Discovers series has been planned to run as many as 24 volumes, and at least three more books are in various stages of production, Target Books cancels the series after this release, citing poor sales.

May

 * 18 - DWN: Doctor Who and the Tomb of the Cybermen was first published.

June

 * 29 - DWN: Doctor Who and the Time Warrior was first published.

July

 * 14 - Jack Woolgar died.
 * 20 - DWN: Doctor Who - Death to the Daleks was first published.

August

 * 29 - Tom Baker and Mary Tamm were interviewed on BBC Radio 2's Pete Murray's Open House.

September

 * Doctor Who Annual 1979 was published.
 * Terry Nation's Dalek Annual 1979 was published. This was the final release of the series.
 * 2 - DW: The Ribos Operation Part 1 was first broadcast. Mary Tamm joins as new companion Romana. Also first appearance of K-9 Mark II. This launched Season 16 (although it was promoted as the show's 15th anniversary), and the series' first season-long story arc, The Key to Time.
 * 9 - DW: The Ribos Operation Part 2 was first broadcast.
 * 16 - DW: The Ribos Operation Part 3 was first broadcast.
 * 23 - DW: The Ribos Operation Part 4 was first broadcast.
 * 30 - DW: The Pirate Planet Part 1 was first broadcast. First Doctor Who Part to be written by Douglas Adams.

October

 * 5 - May Warden, who played the aged Sara Kingdom in DW: The Daleks' Master Plan, died.
 * 7 - DW: The Pirate Planet Part 2 was first broadcast.
 * 14 - DW: The Pirate Planet Part 3 was first broadcast.
 * 21 - DW: The Pirate Planet Part 4 was first broadcast.
 * 28 - DW: The Stones of Blood Part 1 was first broadcast, marking the start of the 100th TV story.

November

 * 04 - DW: The Stones of Blood Part 2 was first broadcast.
 * 11 - DW: The Stones of Blood Part 3 was first broadcast.
 * Vivienne Bennett, who played Queen Elizabeth I in DW: The Chase'', died in London.
 * 16 - DWN: Doctor Who and the Android Invasion was first published.
 * 18 -DW:  The Stones of Blood Part 4 was first broadcast.
 * 22 - Tom Baker, Mary Tamm and Carole Ann Ford appear on the BBC's Nationwide to celebrate Doctor Who's 15th Anniversary.
 * 25 - DW: The Androids of Tara Part 1 was first broadcast.
 * 28 - André Morell, who played Marshal Gaspard de Saux-Tavannes in DW: The Massacre of St Bartholomew's Eve, died in London.

December

 * During a break in production of DW: The Armageddon Factor, Mary Tamm, Tom Baker and John Leeson performed a brief skit for the BBC staff Christmas video in which the Doctor and Romana flirt with each other over a bottle of whiskey and K-9 tries to sing "We Wish You a Merry Christmas". Titled "Doug Who?", the skit circulated unofficially for years before being released in the Key to Time DVD set.
 * 2 - DW: The Androids of Tara Part 2 was first broadcast.
 * 7 - DWN: Doctor Who and the Sontaran Experiment was first published.
 * 09 - DW: The Androids of Tara Part 3 was first broadcast.
 * 16 - DW: The Androids of Tara Part 4 was first broadcast.
 * 23 - DW: The Power of Kroll Part 1 was first broadcast.
 * 30 - DW: The Power of Kroll Part 2 was first broadcast.

Unknown dates

 * American publisher Aeonian Press obtains the US publication rights to some of the Target Books releases, issuing them in limited distribution hardcovers. Among the books reissued in this format are DWN: Doctor Who and the Day of the Daleks and DWN: Doctor Who and the Giant Robot.
 * Eve Myles, who played Gwen Cooper in Torchwood and Gwyneth in DW: The Unquiet Dead, was born in Ystradgynlais, Wales.
 * Tom Baker moonlights from Doctor Who to appear in another BBC series, Late Night Story, which featured Baker performing dramatic readings of horror stories. At least five Part, all between 13 and 15 minutes each, are recorded, but the series was never broadcast. Decades later, the five extant episodes were included as a bonus feature in the DVD box set of The Key to Time.