1975

History of the Doctor Who Universe

 * Events of DW: The Web of Fear (Note: This is the dating suggested in the actual story, though it contradicts the dating suggested for other UNIT era stories, and is itself contradicted by "Downtime." See UNIT dating controversy and "No Future" for further explanation.)
 * On Earth, the introduction of the Betamax videotape recording system officially launches the home video era, although the VHS tape, released in 1976, would ultimately become the dominant home video format for the next 25 years. Among those interested in the new industry is time-displaced Billy Shipton who, acting on instructions received from the Doctor years earlier, enters into the video publishing industry in preparation for his ultimate involvement in DVD authoring decades later. (DW: Blink)

January to April

 * The stage play Doctor Who and the Daleks in The Seven Keys to Doomsday tours the UK.

January

 * DWN: Doctor Who and the Curse of Peladon First Published.
 * 4 - DW: Robot Episode 2 First Broadcast
 * 11 - DW: Robot Episode 3 First Broadcast
 * 18 - DW: Robot Episode 4 First Broadcast
 * 25 - DW: The Ark in Space Episode 1 First Broadcast. Although there would be two more UNIT stories over the next year, this episode marked the end of the Doctor's continued involvement with UNIT.

February

 * 01 - DW: The Ark in Space Episode 2 First Broadcast.
 * 08 - DW: The Ark in Space Episode 3 First Broadcast
 * 15 - DW: The Ark in Space Episode 4 First Broadcast
 * 20 - DWN: Doctor Who and the Cybermen First Published.
 * 22 - DW: The Sontaran Experiment Episode 1 First Broadcast

March

 * 01 - DW: The Sontaran Experiment Episode 2 First Broadcast
 * 08 - DW: Genesis of the Daleks Episode 1 First Broadcast
 * 10 - Yee Jee Tso, who portrayed Chang Lee in the 1996 Doctor Who television movie, is born.
 * 13 - DWN: Doctor Who and the Giant Robot First Published. First novelisation of a Fourth Doctor serial and the first novelisation to be published during the same TV season in which the adapted serial (DW: Robot) was actually broadcast.
 * 15 - DW: Genesis of the Daleks Episode 2 First Broadcast
 * 22 - DW: Genesis of the Daleks Episode 3 First Broadcast
 * 29 - DW: Genesis of the Daleks Episode 4 First Broadcast

April

 * 05 - DW: Genesis of the Daleks Episode 5 First Broadcast
 * 12 - DW: Genesis of the Daleks Episode 6 First Broadcast
 * 19 - DW: Revenge of the Cybermen Episode 1 First Broadcast
 * 23 - William Hartnell, the first actor to portray the Doctor, dies at Marden, Kent, England.
 * 26 - DW: Revenge of the Cybermen Episode 2 First Broadcast

May

 * 03 - DW: Revenge of the Cybermen Episode 3 First Broadcast
 * 10 - DW: Revenge of the Cybermen Episode 4 First Broadcast, bringing Season 12 to a premature end following the BBC's decision to reschedule the originally planned season finale, Terror of the Zygons to the start of Season 13.
 * 15 - DWN: Doctor Who and the Terror of the Autons First Published.

July

 * 15 - Raf De La Torre, who played the Senior Judge in DW: The Keys of Marinus, dies.

August

 * 21 - DWN: Doctor Who and the Green Death First Published.
 * 23 - Tom Baker presents Disney Time in character as the Fourth Doctor
 * 30 - DW: Terror of the Zygons Episode 1 First Broadcast, opening Season 13 and marking the first autumn start for a Doctor Who season since 1968-69.

September

 * 06 - DW: Terror of the Zygons Episode 2 First Broadcast
 * 13 - DW: Terror of the Zygons Episode 3 First Broadcast
 * 20 - DW: Terror of the Zygons Episode 4 First Broadcast. Ian Marter leaves the series as a regular with this episode, although he will return a few weeks later in The Android Invasion on a non-companion capacity. This is also Nicholas Courtney's final regular appearance as Brigadier Alistair Gordon Lethbridge-Stewart; he will next play the character in the 1983 serial Mawdryn Undead. Although UNIT returns in The Android Invasion, this being the last appearance of the Brigadier marks this as officially the end of the UNIT era.
 * 27 - DW: Planet of Evil Episode 1 First Broadcast

October

 * 04 - DW: Planet of Evil Episode 2 First Broadcast
 * 11 - DW: Planet of Evil Episode 3 First Broadcast
 * 16 - DWN: Doctor Who and the Planet of the Spiders First Published.
 * 18 - DW: Planet of Evil Episode 4 First Broadcast
 * 25 - DW: Pyramids of Mars Episode 1 First Broadcast

November

 * 01 - DW: Pyramids of Mars Episode 2 First Broadcast
 * 08 - DW: Pyramids of Mars Episode 3 First Broadcast
 * 15 - DW: Pyramids of Mars Episode 4 First Broadcast
 * 20 - DWN: Doctor Who - The Three Doctors First Published. First novelisation not to use the title form Doctor Who and the .... This is also the first Target Books-commissioned novelisation to feature the First Doctor.
 * 22 - DW: The Android Invasion Episode 1 First Broadcast
 * 29 - DW: The Android Invasion Episode 2 First Broadcast

December

 * 06 - DW: The Android Invasion Episode 3 First Broadcast
 * 13 - DW: The Android Invasion Episode 4 First Broadcast. Final appearances of Ian Marter as Harry Sullivan, John Levene as  John Benton and, as a regular part of the series, UNIT.
 * 16 - Noel Clarke, who plays Mickey Smith in series 1, 2 and (as a one off appearance) 4 of the revived Doctor Who, is born.

Unknown

 * Anna-Louise Plowman, the actor who played Diana Goddard, is born.