The series was conceived by producer James Middleton after Terminator 3 came out, as he found himself missing the character of Sarah Connor and wondered how to bring her back.

Creator Josh Friedman treats the show as an alternate sequel to Terminator 2, disregarding Terminator 3, and views it as existing in its own alternate timeline rather than strict franchise canon.

Friedman originally wanted to make Kyle Reese a regular present-day character without disrupting the film continuity, but the idea was deemed too confusing, leading to the creation of his brother Derek Reese instead.

The show was originally titled simply 'The Sarah Connor Chronicles,' with 'Terminator' added later to capitalize on franchise name recognition after debate during pre-production.

Lena Headey was cast after Friedman auditioned over 300 actresses for Sarah Connor; her casting drew criticism from fans and critics who felt she didn't resemble the muscular warrior Linda Hamilton portrayed in Terminator 2.

Summer Glau, cast as the Terminator Cameron, had not seen any of the Terminator films before being cast and almost skipped the audition because she felt she didn't have the right 'Terminator look'; her character's name is a homage to franchise creator James Cameron.

Shirley Manson, lead singer of the band Garbage, made her acting debut playing the shapeshifting Terminator Catherine Weaver in season two after being recommended due to her friendship with Friedman's wife.

Arnold Schwarzenegger was discussed as a possible guest appearance, but producers noted he was too busy as California governor and too expensive as a star, and Friedman was ultimately opposed to bringing back film actors to avoid overshadowing the new cast.

Production of the first season was disrupted by the 2007-2008 Writers Guild of America strike, cutting the original 13-episode order down to nine completed episodes, with four remaining unfilmed due to lack of finished scripts.

The season-one finale features a scene where Cromartie massacres FBI agents, shot entirely from the bottom of a swimming pool as bodies are tossed in off-screen; the idea was inspired by how the show Rescue Me depicted fires with their own point of view.

For legal reasons related to franchise rights, the show could not reuse the T-800 endoskeleton design from the films, so visual effects supervisor Jim Lima created a new model called the T-888 instead.

Composer Bear McCreary recorded metallic sounds using oil cans, whale drums, chains, anvils, brake drums, garbage cans, and thundersheets to build a custom library of metallic percussion for the score.

Because of financial constraints, Brad Fiedel's iconic Terminator film theme is used only briefly in the TV series, mainly during the title sequence, with McCreary composing original character themes instead.