21 May (releases)

* 1966 - "The O.K. Corral" was broadcast on BBC1.
* 1966 - Part one of the TV Comic story The Secret of Gemino was first published.
* 1977 - Part two of the TV Comic story Kling Dynasty was first published.
* 1981 - The Doctor Who Programme Guide was first published by Target Books.
* 1987 - The Doctor Who Fun Book and the novelisation of The Faceless Ones was first published by Target Books.
* 2001 - The audio story Loups-Garoux was first released by Big Finish Productions.
* 2002 - The audio story The Time of the Daleks was first released by Big Finish Productions.
* 2005 - The Empty Child was first broadcast on BBC One. Later, Special Effects aired on BBC Three.
* 2009 - DWA 116 was first released by BBC Magazines.
* 2011 - The Rebel Flesh was first broadcast on BBC One. Later, Double Trouble aired on BBC Three.
* 2015 - Suburban Hell was first released by Big Finish.
* 2015 - The novelisation of City of Death was published by BBC Books and released as an audiobook by BBC Audio.
* 2015 - DWA15 2 was first released by Panini Comics.
* 2015 - DWFC 46 was first released by Eaglemoss Collections.
* 2020 - The Third Alien Worlds Collection was first released by BBC Audio.
* 2021 - The audiobook version of 666 Charing Cross Road was first released by Big Finish.