On 18 December, a number of things set in or relevant to the Doctor Who universe were released or published.
- 1965 - "Coronas of the Sun" was first broadcast on BBC1.
- 1965 - Part four of the TV Comic story Shark Bait was first published.
- 1971 - Part five of The Eternal Present was first published in Countdown.
- 1976 - Part one of the TV Comic story Dredger was first published.
- 1997 - DWM 260 was first released by Marvel Comics.
- 2000 - The Secret of Cassandra and The Mutant Phase were first released by Big Finish Productions.
- 2003 - Episode six of Scream of the Shalka was first released online.
- 2003 - Companion Piece was first published by Telos Publishing.
- 2006 - Time Flies aired on BBC Three.
- 2008 - The Doctor Who Adventures comic story Frosty the Snowdemon was first published.
- 2010 - Regeneration was first broadcast on Disney XD.
- 2012 - Devil in the Smoke was first published by BBC Digital.
- 2013 - Prisoners of Time: Volume 3 was released by IDW Publishing.
- 2013 - The Mega was first released by Big Finish Productions, and Night of the Stormcrow became available for general release.
- 2014 - Engines of War and Silhouette were released as talking books by BBC Audio.
- 2014 - Toby Hadoke's Who's Round 96 was released online.
- 2014 - DWMSE 39 was first released by Panini Comics.
- 2017 - The Night Before Christmas was released by Big Finish Productions.
- 2017 - Message in the Cards was first published by Thebes Publishing.
- 2019 - The Torchwood audio story Expectant was first released by Big Finish.