Biography: Kurt Johnstad is an American screenwriter. He has worked on several films including 300, for which he was nominated for a Saturn Award, along with Michael Gordon and Zack Snyder. He also wrote the screenplays for Act of Valor, 300: Rise of an Empire and Atomic Blonde, and was tapped to write one of two competing screenplays for Aquaman; Will Beall's script was eventually chosen for the film.