Cecilia Kass is a fictional character from the 2020 film The Invisible Man, directed by Leigh Whannell. She is portrayed by actress Elisabeth Moss. In the film, Cecilia is a woman who escapes an abusive relationship with her wealthy and controlling partner, Adrian Griffin, who is a brilliant scientist. After Adrian's apparent suicide, Cecilia believes she is being stalked by his invisible presence. The story follows her struggle to prove her sanity and fight against the psychological torment she experiences. The film explores themes of abuse, trauma, and the quest for empowerment.