Reports indicate that Taylor Sheridan is writing the screenplay for Sicario 3. Sheridan served as the screenwriter for the first two films. While there have been previous announcements about the production of the third film moving forward, the full creative team and cast lineup have yet to be determined.
Sicario was released in 2015, followed by the sequel Sicario: Day of the Soldado in 2018. The third film has been in development in various forms since 2018 and is often referred to as "Sicario: Capos".
Regarding the cast, Josh Brolin has confirmed his return for the third installment and stated in a recent interview that filming is expected to begin soon. There is currently no confirmed news on whether Benicio del Toro will return.
The first film was directed by Denis Villeneuve, while the second was directed by Stefano Sollima. The director for Sicario 3 and the specific start date for filming are still to be confirmed.