A Girl's Best Friend (TV story)

A Girl's Best Friend was a single-episode story produced in 1981 as a pilot for a potential Doctor Who spin-off called K9 and Company. It was written by Terence Dudley, directed by John Black and featured Elisabeth Sladen as Sarah Jane Smith and John Leeson as K9.

It formally introduced K9 Mark III, the third iteration of K9 robots, first referenced in the short story Inter-Galactic Cat.

The BBC chose not to commission a new series but did televise the episode as a holiday season special. It was only the second story of this kind in the Doctor Who franchise, preceded by more than a decade by "The Feast of Steven", a Christmas Day "break" from The Daleks' Master Plan. With a run time of 50 minutes, it was the first single episode in a Doctor Who-related TV production to exceed a half-hour in length.

This was the only attempt at a spin-off series during the original run of Doctor Who to reach production. It would be more than a quarter-century until this was attempted again. Furthermore, its studio filming was unusually completed at Pebble Mill Studios in Birmingham making it one of only two stories of the "classic" era (the other being Horror of Fang Rock) to have the bulk of its studio recording completed outside Greater London.

6 out of 17 (35.3%) raters say this story requires a previous story.