The success of a claustrophobic thriller rests squarely on performance chemistry. It's Me, Jessica! sidesteps traditional stunt casting in favor of stage-trained actors who can balance manic energy with grounded panic.
- Maya Lindqvist as Jessica / The Imposter: Lindqvist turns in a tour-de-force performance. Slipping between a disarming girl-next-door persona and a predatory, unblinking menace, she delivers the titular line with dozens of chilling intonations.
- Julian Vance as Arthur Ross: Arthur is an emotionally exhausted archivist who returns to his childhood estate following a family bereavement. Julian Vance plays him with a fraying vulnerability that anchors the escalating madness.
- Tamara Kincaid as Detective Miller: The cynical local deputy who suspects Arthur is staging the harassment for insurance money. Kincaid supplies the sharp, dry wit that keeps the second act grounded.
- Arthur's estranged half-brother whose unexpected arrival throws the household power dynamics into complete chaos.
Industry observers noted casting rumors connecting established names to early table reads. While Jessica Barden and Jessica Chastain, the latter known for her collaborations with auteur Michel Franco on projects like Dreams, were widely mentioned across fan casting forums, director Marcus Vance insisted on casting Lindqvist to prevent audience preconceptions from diluting the mystery.
