Chastain horror Other Mommy opens 9 October eyeing $20m debut

Jessica Chastain's horror film Other Mommy opens in the United States on 9 October with an estimated $20 million debut in its sights.

That figure would put it first for the weekend at the domestic box office, the United States and Canada, according to The Hollywood Reporter. Universal Pictures lists the film for 9 October 2026, according to Universal Pictures. NBCUniversal also confirmed a 9 October release for the Chastain-led horror film, according to NBCUniversal.

Chastain plays two roles. She is Bela's mother and she is Other Mommy. Arabella Olivia Clark plays her daughter, who is haunted by a demonic entity. The set-up gives Chastain scenes opposite herself as mother and monster.

The story is based on Josh Malerman's novel Incidents Around the House. Rob Savage directs. The film is a Blumhouse/Atomic Monster production for Universal, which is handling the cinema release.

Universal held its official US critics screenings until the last minute. Previews played in New York and Los Angeles before the Friday opening. Full reviews therefore emerged very close to the first public shows.

The international roll-out starts around the same date. In New Zealand, Universal Pictures NZ advertised the film as in cinemas on 8 October, according to Universal Pictures NZ. The US opening follows a day later.

Savage has said the film includes around 50 jump scares. Jump scares are sudden shocks of sound and image built to make an audience jump. Fifty is a lot. It tells ticket buyers what kind of screening to expect.

Early response has been blunt in places. One early reaction quoted by The Hollywood Reporter called the film a hot mess and Chastain's worst movie in a long time. That line circulated before the wider reviews appeared on 8 October.

For audiences, this means a clear weekend choice. A star-led horror film opens wide in October. Monday's actuals will show where it landed.