Other Mommy: How Scary Is the New Movie?

TL;DR — Other Mommy releases in theaters October 9, 2026, starring Jessica Chastain as a sinister entity that impersonates an 8-year-old girl's mother. Directed by Rob Savage (Host, The Boogeyman) and produced by James Wan, it's based on Josh Malerman's novel — the same author who wrote Bird Box. Based on the trailer and creative team, this looks genuinely unsettling rather than jump-scare-driven, so here's what to actually expect.

What is Other Mommy about?

Bela, an 8-year-old girl living in a home already strained by her parents' marital problems, begins encountering a sinister entity that emerges from her closet — one that looks and sounds exactly like her mother. The presence, which Bela calls "Other Mommy," grows increasingly threatening to her and her family as the story unfolds, forcing Bela to decide who she can actually trust in her own home.

Who's involved in making Other Mommy, and who's in the cast beyond Chastain?

Jessica Chastain plays Ursula, Bela's real mother, alongside the impersonating entity. Arabella Olivia Clark plays Bela. Jay Duplass plays Russ, Bela's father, with Dichen Lachman, Arian Moayed, Sean Kaufman, Adam Silver, and Rosie Anne O'Gorman rounding out the cast, alongside Karen Allen as Grandma Ruth. Rob Savage directs — known for Host and The Boogeyman, both genuinely effective, tension-driven horror rather than gore-focused films. James Wan produces through Atomic Monster, alongside Blumhouse Productions. The screenplay comes from Nathan Elston (a WGA Award winner for his work onSuccession), based on Josh Malerman's novel Incidents Around the House — Malerman also wrote Bird Box, which should tell you something about the kind of dread this is going for.

When and where was it filmed, and why did the release date move?

Production ran May 12 through July 9, 2025, in Dublin, Ireland. The film was originally scheduled for a May 8, 2026 release before Universal pushed it to October in September 2025, landing it in the more natural pre-Halloween horror window instead — generally a sign of confidence in a horror release rather than a red flag, since studios more often push a film they're worried about into a dump month, not toward the single biggest horror moviegoing weekend of the year.

When does Other Mommy come out, and where can I watch it?

Other Mommy releases in U.S. theaters on October 9, 2026, distributed by Universal Pictures. It's a theatrical release only for now, with no streaming date confirmed.

How scary does Other Mommy actually look, and what does the R rating confirm?

Here's the honest read, using the same approach we'd recommend for judging any horror film before committing: check what kind of scary it's actually going for, not just a vague "is it scary" question. The film has since been officially rated R, for "some bloody violence, and language" — a real, official data point rather than just trailer speculation, and one that confirms this isn't aiming for a softer, PG-13 crowd-pleaser register.

This looks like dread-driven horror, not jump-scare horror. The premise — a family member's exact double, but wrong — is built around slow-building distrust and uncanny valley discomfort rather than sudden shocks. Rob Savage's prior work (Host, The Boogeyman) leans the same direction: tension that builds rather than jolts you. The trailer itself, out since July 21, backs that up — described by early reactions as "legitimately scary" rather than gimmicky, with viewers specifically calling out the compelling craft of the preview itself rather than just its jump scares.

Jessica Chastain's dual-purpose casting is doing real work here. Playing both the real mother and the entity impersonating her means the horror lives in subtle physical and tonal shifts — a performance-driven kind of unease rather than makeup-heavy creature-horror.

The "child in danger" element is worth knowing if that's a specific sensitivity for you. Bela is 8 years old and central to the story's threat, which is a real, specific trigger for some viewers regardless of how the scares are delivered.

Should you be excited for this one?

If body-double dread and slow-building distrust (think The Substance's uncanny-double tension, applied to a family horror setting) appeals to you more than jump scares, this looks like a genuinely strong pick for the October horror season. If gore or fast-paced scares are what you're after specifically, this looks built for a different kind of unease entirely.

Frequently asked questions

Is Other Mommy based on a true story? No — it's based on Josh Malerman's 2024 novel Incidents Around the House, a work of fiction.

When does Other Mommy release? October 9, 2026, in U.S. theaters.

Who plays the villain in Other Mommy? Jessica Chastain plays both Bela's real mother and the sinister entity impersonating her.

Is Other Mommy connected to Bird Box? No direct connection — but it's written by the same novelist, Josh Malerman, so fans of Bird Box's slow-building dread may recognize a similar sensibility.

What is Other Mommy rated, and what does that confirm about how scary it is? It's officially rated R, for "some bloody violence, and language." That's a real, official confirmation of the dread-driven read above, not just speculation from the trailer.

Where was Other Mommy filmed? Dublin, Ireland, with production running May 12 through July 9, 2025.

Want to check if this one fits your scare tolerance specifically?

We've written a full guide on how to know if a horror movie is too scary for you before committing to watch it — worth a read before October 9 if horror is hit-or-miss for you specifically.