1970

August

 * 20 - Ace, companion of the Seventh Doctor, is born in England. (DW: Ghost Light)

Unknown date

 * "Mary" kills Myra Bennett in order to consume her heart. Human authorities do not manage to catch her. (TW: Greeks Bearing Gifts)

January

 * 3 - DW: Spearhead from Space Episode 1, the first colour episode of Doctor Who, the first of Season 7, and the first starring Jon Pertwee as the Third Doctor is first broadcast. It launches the "UNIT era" of the series. Beginning in 1970, the number of episodes produced in each season is reduced considerably, and the show moves from a Fall to Spring broadcast schedule to a January-June schedule. Caroline John debuts as companion Liz Shaw, while Nicholas Courtney, as Brigadier Alistair Gordon Lethbridge-Stewart, becomes a series regular with this episode.
 * 10 - DW: Spearhead from Space Episode 2 is first broadcast.
 * 17 - DW: Spearhead from Space Episode 3 is first broadcast.
 * 24 - DW: Spearhead from Space Episode 4 is first broadcast.
 * 29 - Jon Pertwee discusses the Doctor’s new car, Bessie, in the pages of Radio Times.
 * 31 - DW: Doctor Who and the Silurians Episode 1 is first broadcast. The Doctor's car, Bessie, appears for the first time. This is the only televised story to use the Doctor Who and the ... title format, as a result of a clerical error.

February

 * 7 - DW: Doctor Who and the Silurians Episode 2 is first broadcast.
 * 14 - DW: Doctor Who and the Silurians Episode 3 is first broadcast.
 * 21 - DW: Doctor Who and the Silurians Episode 4 is first broadcast.
 * 27 - The BBC's Audience Research Dept. files an Audience Research Report on DW: Spearhead from Space Episode 1. The episode rates a Reaction Index of 54, with new Doctor Jon Pertwee having been "accepted without question".
 * 28 - DW: Doctor Who and the Silurians Episode 5 is first broadcast.

March

 * 7 - DW: Doctor Who and the Silurians Episode 6 is first broadcast.
 * 14 - DW: Doctor Who and the Silurians Episode 7 is first broadcast.
 * 21 - DW: The Ambassadors of Death Episode 1 is first broadcast.
 * 28 - DW: The Ambassadors of Death Episode 2 is first broadcast.

April

 * 4 - DW: The Ambassadors of Death Episode 3 is first broadcast.
 * 11 - DW: The Ambassadors of Death Episode 4 is first broadcast.
 * 18 - DW: The Ambassadors of Death Episode 5 is first broadcast.
 * 25 - DW: The Ambassadors of Death Episode 6 is first broadcast. First UNIT-era appearance of John Levene as Sgt. Benton, who becomes a semi-regular for the next 6 years.

May

 * 2 - DW: The Ambassadors of Death Episode 7 is first broadcast.
 * 9 - DW: Inferno Episode 1 is first broadcast.
 * 16 - DW: Inferno Episode 2 is first broadcast.
 * 23 - DW: Inferno Episode 3 is first broadcast.
 * 30 - DW: Inferno Episode 4 is first broadcast.

June

 * 6 - DW: Inferno Episode 5 is first broadcast.
 * 13 - DW: Inferno Episode 6 is first broadcast.
 * 20 - DW: Inferno Episode 7 is first broadcast, concluding Season 7, which is the shortest season to date and the shortest-ever season in terms of number of serials until Season 23's single-story marathon. Caroline John leaves the series after this episode.

July

 * 10 - John Simm is born.

September

 * Publication of the sixth Doctor Who Annual.

October

 * 05 - In the US, the National Educational Television network is rebranded and relaunched as the Public Broadcasting Service (PBS). This loose affiliation of broadcasters will introduce countless UK-produced television programs to North American audiences over the next four decades, and become the primary broadcast home of the 1963-89 version of Doctor Who beginning in the late 1970s.

November

 * 06 - Colin Baker makes his TV acting debut in an episode of The Adventures of Don Quick.