On 21 January, a number of things set in or relevant to the Doctor Who universe were released or published.
- 1967 - Episode two of The Underwater Menace was first broadcast on BBC1.
- 1967 - Part one of the TV Comic story The Trodos Ambush was first published.
- 1978 - Part three of Underworld was first broadcast on BBC1.
- 1978 - Part two of the TV Comic story The Snow Devils was first published.
- 1988 - The novelisation of The Rescue was first released in paperback by Target Books.
- 1993 - DWM 196 was first released by Marvel Comics.
- 2002 - The audio story Project: Infinity was released by Big Finish Productions.
- 2007 - Immortal Beloved was broadcast on BBC7.
- 2009 - The Doctor Who: Battles in Time comic story Metal Mania was first published.
- 2010 - Doctor Who at the BBC: A Legend Reborn was first released by BBC Audio.
- 2010 - The Doctor Who Adventures comic story The Unwelcome Visitors was first published.
- 2020 - Dark Universe was first released by Big Finish Productions.