In 2006, Children's BBC wanted a Doctor Who spin-off originally conceived as a drama about a young Doctor Who, but Russell T Davies vetoed the idea, arguing it would undermine the mystery of the Doctor's origins.

Davies suggested basing the new series on the Doctor's former companion Sarah Jane Smith instead, and the project was first confirmed by the BBC's internal newsletter Ariel in August 2006 under the working title 'Sarah Jane Investigates'.

A 1981 pilot for another Sarah Jane spin-off, K-9 and Company, was never picked up as a full series, decades before The Sarah Jane Adventures was made.

K9 barely appeared in the first two series (just a cameo in the special and the series one finale) because an independently produced K9 series was being developed concurrently with a remodelled version of the robot dog.

Nicholas Courtney's appearance as Brigadier Lethbridge-Stewart in 'Enemy of the Bane' (2008) turned out to be his final performance as the character before his death in 2011.

Matt Smith's Eleventh Doctor was originally meant to appear in the episode 'Sky', but scheduling conflicts prevented his participation.

Following Elisabeth Sladen's death on 19 April 2011, only three of the six planned two-part serials for series five had been completed, and the BBC announced no further episodes would be produced, leaving several plot points unresolved.

The script for the unfilmed Sarah Jane Adventures episode 'The Thirteenth Floor' was later rewritten and broadcast as an episode of the spin-off series Wizards vs Aliens.

A 13-minute tribute webcast titled 'Farewell, Sarah Jane', written by Russell T Davies, aired online on 19 April 2020 to mark the anniversary of Elisabeth Sladen's death, featuring a memorial service for Sarah Jane attended by the show's regular cast.

The first series scored 66 out of 100 on Metacritic based on five critics, and reviews grew mixed over time, with some praising series two as an improvement while another critic panned it for poor scripts and acting.