The post-apocalyptic sci-fi drama is based on the 1974 Robert C O'Brien novel of the same title, reported Deadline.
"Z for Zachariah" stars Margot Robbie as 16-year-old Ann Burden, the only survivor in a small US town after a nuclear war.
Her solitude is interrupted when two strangers - a brooding scientist named Loomis (Chiwetel Ejiofor) and an unsettling third survivor named Caleb (Chris Pine) - emerge from the woods.
The film debuted at the Sundance Film Festival in January.
"Z for Zachariah" will be released on August 21 in the US. A UK release date has yet to be announced.