According to The Hollywood Reporter, Hauser will take on the titular role in "The Ballad of Richard Jewell", which will centre on the man wrongly accused of planting the bomb he found in a bag at the Atlanta Olympics in Georgia.
The 32 year old's casting emerges days after Oscar winner Sam Rockwell entered negotiations to portray Jewell's attorney.
Eastwood will direct the project, which was originally set up at 20th Century Fox in 2014, before being picked up by Warner Bros. bosses last month.
Jonah Hill and his "The Wolf of Wall Street" co-star Leonardo DiCaprio, who had previously been attached to take on the two leads, will serve as producers on the movie, which is based on a Vanity Fair magazine article by Marie Brenner.
Jewell's life was turned upside down within days of discovering the backpack containing the explosive.
After initially being hailed a hero, his fortunes took a nosedive as local media outlets reported that Jewell had become a suspect, leaving his reputation in tatters.
He was eventually cleared of the charge three months later, and went on to become a police officer. He soon died of heart failure, aged 44.