Also new to the cast is Jonathan Tucker, one of the stars of Haggis' NBC midseason drama "The Black Donnellys."
Based on the Mark Boal Playboy article "Death and Dishonor," "Elah" is set to begin production later this month in New Mexico and Morocco for Warner Independent.
The film tells the story of a father (Jones) searching for his son (Tucker), an Iraq veteran gone AWOL. He uncovers a murder mystery. Sarandon will play the wife of Jones' character, in a reunion of stars from "The Client."
Sarandon is currently shooting "The Battle in Seattle," co-starring Theron. Other upcoming roles for the "Dead Man Walking" star include "Enchanted" and "Mr. Woodcock."
Tucker's also been seen in the features "Hostage," "Pulse" and "Criminal."