20 January (releases)

* 1966 - The Thunderbirds episode The Man from MI.5 was first broadcast on ITV.
* 1968 - Episode five of The Enemy of the World was first broadcast on BBC1.
* 1968 - Part four of the TV Comic story The Witches was first published.
* 1973 - Episode four of The Three Doctors was first broadcast on BBC1.
* 1973 - Part one of the TV Action comic story Deadly Choice was first published.
* 1977 - The novelisation of Carnival of Monsters was first published by Target Books.
* 1979 - Part one of The Armageddon Factor was first broadcast on BBC1.
* 1979 - Part six of the TV Comic story The Metal-Eaters was reprinted as a Fourth Doctor story.
* 1984 - Part two of The Awakening was first broadcast on BBC1.
* 1994 - Conundrum was first published by Virgin Books.
* 1994 - DWM 209 was first published by Marvel Comics.
* 1996 - Episode one of The Ghosts of N-Space was first broadcast on BBC Radio.
* 2004 - The audio story The Creed of the Kromon was first released by Big Finish Productions.
* 2007 - The audio anthology Circular Time was released by Big Finish.
* 2011 - DWA 201 was first released by BBC Magazines.
* 2013 - talespinning was first released by Telos Publishing.
* 2014 - The Time of the Doctor was released on Region 2 DVD and Blu-ray.
* 2021 - The Fourth Doctor Adventures Series 10: Volume 1 was first released by Big Finish.
* 2022 - The Eternal Mystery was first released on YouTube.