The Bletchley Circle: San Francisco is a British-Canadian television drama series that premiered in the United Kingdom on ITV on 25 July 2018, in the United States on BritBox on 26 July 2018, and in Canada on Citytv on 14 September 2018.A spin-off of the miniseries The Bletchley Circle, the new series follows Millie (Rachael Stirling) and Jean (Julie Graham) as they travel to San Francisco and continue to use their code-breaking skills to solve murders.The Bletchley Circle: San Francisco is produced by Omnifilm Entertainment and World Productions for BritBox, with Kew Media as the international distributor. Filming began in March 2018 and takes place principally in Vancouver, British Columbia.Following a successful debut season, Rachael Stirling and Julie Graham confirmed during an interview with Total TV Guide in April 2019 that a second series had been commissioned. The complete first series was released on DVD in Region 2 by Acorn Media on 20 May 2019.