Etan Cohen will write and direct the pic.
The film will be produced by Mosaic and Gary Sanchez Productions with Jimmy Miller producing on Mosaic’s behalf and Adam McKay producing on behalf of Gary Sanchez.
Brydon will play the head of Scotland Yard, Inspector Lestrade. Macdonald will play Holmes’ housekeeper, and Hall will play Dr. Grace Hart, the first female doctor to practice in London.
Jonathan Kadin is overseeing the project for Columbia; Chris Henchy and Jessica Elbaum are overseeing for Gary Sanchez.
Production is set to start in the first quarter of next year.
Brydon’s past credits include “The Trip” opposite Steve Coogan and “The Huntsman: Winter’s War.”
Macdonald is best known for her work on “Boardwalk Empire” and was most recently seen in Netflix’s comedy “Special Correspondents,” written and directed by Ricky Gervais. She is repped by ICM Partners and Independent Talent Group in the U.K.
Hall was most recently seen in “Christine,” which is already drumming up best actress Oscar buzz. She is repped by WME and Julian Belfrage Associates.
Deadline Hollywood first reported the news.