1968

May

 * Jack Harkness is present for the Parisian student riots. (TWM: The Book of Jahi)

October

 * The Olympics are held in Mexico City (DW: The Underwater Menace and contemporary accounts).

December

 * 20 - Cristian Alvarez meets the Doctor in London. (NA: The Left-Handed Hummingbird)
 * 23 - The Sentience begins stirring in Crook Marsham. (NA: Nightshade)
 * 24 - The Doctor and Ace arrive in Crook Marsham, and become involved in the fight against the Sentience. (NA: Nightshade)
 * 25 - The final battle against the Sentience takes place. It departs Crook Marsham. Actor Edmund Trevithick dies in the incident. (MA: Nightshade)

Unknown dates

 * The United Nations have by this time established protocols for first contact with alien life. (DW: The Sound of Drums)
 * The Monk deposits &pound;200 in a London bank, planning to withdraw it with compound interest in two hundred years (DW: The Time Meddler).

January

 * 06 - DW: The Enemy of the World Episode 3 is first broadcast.
 * 13 - DW: The Enemy of the World Episode 4 is first broadcast.
 * 20 - DW: The Enemy of the World Episode 5 is first broadcast.
 * 27 - DW: The Enemy of the World Episode 6 is first broadcast. The episode is followed by a specially shot scene of the Doctor addressing the viewers about the events of the next story.

February

 * 01 - Tom Baker makes his TV acting debut in an episode of Market in Honey Lane.
 * 03 - DW: The Web of Fear Episode 1 is first broadcast.
 * 10 - DW: The Web of Fear Episode 2 is first broadcast.
 * 17 - DW: The Web of Fear Episode 3 is first broadcast. First appearance of Nicholas Courtney as Col. (later Brigadier) Alistair Gordon Lethbridge-Stewart, a character that will become a consistent part of the Doctor Who universe for the next 40 years.
 * 24 - DW: The Web of Fear Episode 4 is first broadcast.

March

 * 02 - DW: The Web of Fear Episode 5 is first broadcast.
 * 09 - DW: The Web of Fear Episode 6 is first broadcast.
 * 16 - DW: Fury from the Deep Episode 1 is first broadcast.
 * 23 - DW: Fury from the Deep Episode 2 is first broadcast.
 * 30 - DW: Fury from the Deep Episode 3 is first broadcast.

April

 * 04 - Martin Luther King, Jr. is assassinated.
 * 06 - DW: Fury from the Deep Episode 4 is first broadcast.
 * Keith Pyott, who played Autloc in DW: The Aztecs dies.
 * 13 - DW: Fury from the Deep Episode 5 is first broadcast.
 * 20 - DW: Fury from the Deep Episode 6 is first broadcast. Deborah Watling leaves the series with this episode.
 * 27 - DW: The Wheel in Space Episode 1 is first broadcast.

May

 * 04 - DW: The Wheel in Space Episode 2 is first broadcast. Debut of Wendy Padbury as new companion Zoe Heriot.
 * 11 - DW: The Wheel in Space Episode 3 is first broadcast.
 * 12 - Catherine Tate (Donna Noble) is born.
 * 18 - DW: The Wheel in Space Episode 4 is first broadcast.
 * 25 - DW: The Wheel in Space Episode 5 is first broadcast.
 * 28 - Kylie Minogue (Astrid Peth in DW: Voyage of the Damned) is born.

June

 * 01 - DW: The Wheel in Space Episode 6 is first broadcast, concluding the fifth season of Doctor Who. The episode ends with the Doctor proceeding to show Zoe a recording of a recent adventure, leading into a rebroadcast of DW: The Evil of the Daleks which will fill the gap before the start of the next season.
 * 06 - Robert Kennedy is assassinated.

August

 * 5 - Matt Jones, best known in the Doctor Who world for writing the Doctor Who episodes DW: The Impossible Planet/The Satan Pit and the Torchwood episode TW: Dead Man Walking, is born.
 * 10 - DW: The Dominators Episode 1 is first broadcast, launching Season 6.
 * 17 - DW: The Dominators Episode 2 is first broadcast.
 * 24 - DW: The Dominators Episode 3 is first broadcast.
 * 31 - DW: The Dominators Episode 4 is first broadcast.

September

 * Publication of the fourth Doctor Who Annual.
 * 07 - DW: The Dominators Episode 5 is first broadcast.
 * 14 - DW: The Mind Robber Episode 1 is first broadcast.
 * 21 - DW: The Mind Robber Episode 2 is first broadcast.
 * 28 - DW: The Mind Robber Episode 3 is first broadcast.

October

 * Frazer Hines releases the pop single "Who's Dr. Who?" on Major Minor Records.
 * 05 - DW: The Mind Robber Episode 4 is first broadcast.
 * 12 - DW: The Mind Robber Episode 5 is first broadcast, followed by several weeks of preemptions caused by coverage of the 1968 Summer Olympic Games in Mexico City.

November

 * 02 - DW: The Invasion Episode 1 is first broadcast. Terrance Dicks' long association with the Doctor Who franchise begins with this episode, on which he serves as script editor. Although the character is not yet identified by name, John Levene makes his debut as John Benton.
 * 09 - DW: The Invasion Episode 2 is first broadcast, in which UNIT is officially introduced. Alistair Gordon Lethbridge-Stewart appears as a brigadier for the first time, though he won't become a regular until 1970.
 * 16 - DW: The Invasion Episode 3 is first broadcast.
 * 23 - DW: The Invasion Episode 4 is first broadcast; this is also the show's 5th anniversary.
 * 30 - DW: The Invasion Episode 5 is first broadcast.

December

 * 07 - DW: The Invasion Episode 6 is first broadcast.
 * 14 - DW: The Invasion Episode 7 is first broadcast.
 * 21 - DW: The Invasion Episode 8 is first broadcast.
 * 28 - DW: The Krotons Episode 1 is first broadcast. First Doctor Who script for the prolific Robert Holmes.