The 54-year-old actor joins Asher Angel, Jack Dylan Grazer, Grace Fulton, Adam Brody, and Michelle Borth and Ross Butler in the project.
According to Entertainment Weekly, Hounsou will play the role of a sorcerer who gives young Billy Batson (Angel) his powers.
The part was originally attached to "This is Us" actor Ron Cephas Jones, but he evidently left the project due a scheduling conflict.
Hounsou is no stranger to superhero films, having earlier played Korath in the Marvel's "Guardians of the Galaxy".
He will also reprise the role in the upcoming "Captain Marvel".
Directed by David F Sandberg, "Shazam!" will release on April 5 next year.