Jacques Audiard is directing the indie feature, based on Patrick deWitt's novel of the same name. The pic is a co-production between Why Not productions and Page 114. Alison Dickey, John C. Reilly, and Michael De Luca are producing.
Reilly originally optioned the rights to the book. The story follows two brothers - Eli and Charlie Sisters - who are hired to kill a prospector who has stolen from their boss. The story takes place in Oregon in 1851.
It's unknown who Ahmed will play in the film.
Canadian-born author deWitt's novel won the 2012 Stephen Leacock Memorial Medal for humor writing.
"The Sisters Brothers" is Audiard's follow-up to his Palme d'Or winning "Dheepan," which premiered at the 2015 Cannes Film Festival. Production is set to start sometime this summer. The noir Western will be his first film shot completely in English.
Ahmed is coming off a banner year both on the television and film front starring in two of the biz's largest successes starting with HBO's critically acclaimed "The Night Of" which earned Ahmed a SAG nomination. He would follow that up with "Rogue One: A Star Wars Story" and also appeared in "Jason Bourne" opposite Matt Damon.
Ahmed had the Toronto Film Festival pic "The City of Tiny Lights" and a recurring role on Netflix's "The OA." He also had a guest starring role in the final season of HBO's "Girls" that earned him rave reviews.