In what month and year was a third Enola Holmes film announced as in development?

A third Enola Holmes film was announced as in development in November 2024. The announcement introduced the project as a Netflix and Legendary sequel, with Philip Barantini attached to direct and Millie Bobby Brown returning as Enola Holmes.

Brown was also announced as a producer, while the project was described as darker and more mature than the first two films. That announcement established the film’s development status; it was not yet a release-date announcement or confirmation that filming had begun.

The timing is easy to mix up with later production news. Principal photography began in April 2025, and additional returning cast members were confirmed around that period. Those later updates do not change the original announcement month: the project first became public as an in-development film in November 2024.