The adaptation of Maria Semple's novel of the same name, will feature Blanchett as the titular Bernadette, an eccentric former architect who mysteriously disappears from her claustrophobic life in Seattle, according to The Hollywood Reporter.
Bill Crudup and Kristen Wiig also star in the dramedy from director Richard Linklater.
Megan Ellison, Nina Jacobson, Ginger Sledge and Brad Simpson are producing the project.