The film stars Dan Stevens and Maika Monroe, with a supporting cast that includes Leland Orser, Sheila Kelley, Brendan Meyer, and Lance Reddick.

It tells the story of a U.S. soldier (Stevens) called David who unexpectedly visits the Peterson family, introducing himself as a friend of their son who died in combat in Afghanistan.

After he has been staying in their home for a couple of days, a series of deaths occur, and the daughter Anna (Monroe) suspects David is connected to them.

Spencer and Laura Peterson, with their children Luke and Anna, are coping with the loss of their eldest son, Caleb, to the war in Afghanistan.

David hears of Spencer's troubles at work, and he sees Luke return home with a bruise on his face, caused by homophobic bullies at school.

He reveals that David was a test subject in a military medical experiment and was "programmed" to kill anyone who might compromise his identity, and is unlikely to be able to stop even if he wanted to.

Carver and Anna arrive at the school before David, and enter a haunted house set up for the Halloween dance.

David turns off the lights and plays Anna's mix CD, then kills Luke's teacher and Carver with a boxcutter.

As several firefighters exit the school, Anna notices one of them is limping; he turns to face her, and it is David using the disguise to quietly escape the scene.

Simon Barrett, who previously collaborated with Adam Wingard on the films A Horrible Way to Die and You're Next, wrote the script for The Guest.

Barrett said, "one of the things that excites me the most is to have established a pre-existing dynamic like a nuclear family, then introduce an element that's disruptive [...] I love just movies where a stranger comes to town “High Plains Drifter"-style.

[15] The film score was composed by Steve Moore, and includes synthwave tracks from artists such as Clan of Xymox and Survive.

[17][18] Other footage which was edited or deleted after test screenings were scenes which explained what exactly "David" is, what happened to him, why he commits some of the acts in the story, and more details about the KPG program that he was involved in.

Test audiences felt that the plot explanation was too much, a view shared by Wingard and Barrett, who "hated" explaining David's character and his background because they wanted to leave it ambiguous, and were thus happy to cut those scenes from the film.

The site's critics consensus states, "Boasting enough intelligence to bolster its darkly violent thrills, The Guest offers another treat for genre fans from director Adam Wingard.

[33] Robert Abele of the Los Angeles Times described the film as a "dirty-sexy-funny homage to the vise-grip corkers that marked John Carpenter' and James Cameron's indie heyday", and praised Stevens' "killer personality" which brings The Guest to life.

[34] Another critic, Peter Travers of Rolling Stone, also agreed the film was "fun" and praised Stevens' "mesmerizing" performance.

[35] Writing for The New York Times, Jeannette Catsoulis complimented Wingard and Barrett's ability in tackling another familiar genre together; she thought Stevens' performance was restrained but "magnetic" as the story develops.

[36] London Evening Standard's Charlotte O'Sullivan was equally impressed by the director and writer duo; the critic gave the film 4 out of 5 stars and opined that Stevens' was "perfect" for the lead role.

[37] Dennis Harvey of Variety, while critical of the horror homage and ending, thought "The Guest is blood-soaked action trash of a high grade".

The soundtrack features contributions by OGRE Sound, Steve Moore, Ghost Cop, Adam Wingard, Xander Harris, and Lone Runner.

[50] In 2024, Wingard revealed that he and Stevens discussed potential ideas while filming Godzilla x Kong: The New Empire and that he included a track from The Guest 2 soundtrack into the film for fans; the track, "Hardwired" by Jordan F, was featured in a scene where characters played by Stevens, Rebecca Hall, and Kaylee Hottle approach a Hollow Earth aircraft.