Doctor Who universe

The Doctor Who universe or Whoniverse is a term used by fans, and increasingly the mainstream press, to describe the shared fictional universe in which the stories of Doctor Who, K-9 & Company, Torchwood and The Sarah Jane Adventures are set. It has become a more meaningful term since BBC Wales began producing shows which have run concurrently on the BBC.

In particular, the shared nature of this universe has allowed stories begun on one of the shows to be continued on a different series. In some cases, this has meant that important narrative developments—such as Martha Jones' employment by UNIT (TW: Reset), Sarah Jane's conflict with a Sontaran who survived the Tenth Doctor's battle with them in the early 21st century (SJA: The Last Sontaran), or the majority of Gwen and Ianto's lines in DW: The Stolen Earth—cannot be fully understood by watching just one of the programs in isolation.

In other cases, the implications of a shared universe are more subtle, as when technology, concepts or cultures that debuted on one program are briefly referenced on another. This happens with frequency on The Sarah Jane Adventures. In one instance, for example, the planet Draconia, which had been the major focus of DW: Frontier in Space, was casually mentioned as having a well-developed form of astrology (SJA: Secrets of the Stars). In another, Sarah Jane's initial suggestions of "Alistair" and "Harry" as possible names for Luke in SJA: Invasion of the Bane was a subtle reference to Harry Sullivan and the Brigadier—characters who had, at the time, not even been mentioned by a BBC Wales production. Likewise, Sarah's description of the origins of her coulrophobia in SJA: Day of the Clown returns the viewer to the setting of A Girl's Best Friend. While such "crossovers" are not narratively significant, they nevertheless reinforce the notion of a single, shared universe.