9 Greatest Hidden-Gem Horror Masterpieces of the 21st Century, Ranked

Some of the greatest horror movies in history weren't always beloved at first, especially the ones from our current century. Horror is full of those slow successes, the ones that didn't generate much buzz or praise at first, but then slowly garnered a worthy cult following later on. The Thing, The Shining, and Event Horizon are arguably the most iconic examples of reappraised horror masterpieces, and they prove that some of the all-time greats didn't always hit the ground running.

As horror has really kicked things up a notch in the 21st century, it's seen many triumphs but also a great many failures. And stuck in between were the horror gems that were great but aren't the most well-known. The following horrors are prime examples of solid, effective, and even award-worthy efforts that aren't the most remembered, were panned at first, or bombed hard at the box office. From cult classics to misunderstood masterpieces, these are the ten greatest hidden-gem horror movies of the 21st century.

9 'The Dark and the Wicked' (2020)

Arguably, one of the scariest movies of this current decade is one many people don't even know about. From Bryan Bertino, his 2020 underrated horror masterpiece The Dark and the Wicked offers everything that its eerie title entails. It's a frightening mix of supernatural terror and heartbreaking drama, following two estranged siblings as they return to their family farm to say their goodbyes to their dying father, only to realize a sinister demonic presence is lurking over him.

The scares here are unimaginable and highly effective. Some of the scenes are so bleak and distressing that they're sure to leave your jaw dropped. The Dark and the Wicked provides a chilling experience that is unlike any other from this century, despite its familiar tropes and setting. It didn't make any huge impact at the box office due to a limited release, but it's since developed a significant following by those who've come to appreciate its dread tone and shocking scares. Give it a watch, it might just scare you out of your mind.

8 'Tigers Are Not Afraid' (2017)

In this shockingly brilliant international horror gem from 2017, Tigers Are Not Afraid delivers a unique blend of dark fantasy and terror mixed in with a gripping story that says a lot about Mexico's War on Drugs and gang violence. It follows a young girl, orphaned after the cartel murdered her mother, as she goes on a magical but terrifying journey along with a local gang of street orphans, along the way having ghostly encounters with the dead.

Tigers Are Not Afraid is a one-of-a-kind film, one that's sure to leave viewers completely blown away by its haunting imagery and compelling storytelling. This approach allows viewers to see the violent, horrifying world of crime and street gang wars through the eyes of a child and how it's affecting her and everyone around her. It's deep and emotional, and the fantasy elements feel truly fascinating. It's a shame it doesn't get brought up as much, but it can turn anyone who finally sees it into a huge fan.

7 'Pulse' (2001)

2001's Pulse is considered now as one of the scariest horror movies of all time. It's a film straight out of a nightmare, a tense mix of suspense and dread that will leave anyone paranoid long after they've seen it. It follows two people in Japan who slowly discover that the world is headed for disaster, as sinister spirits have found a way to cross from the spirit realm into the material world via the internet.

It's not widely known by most casual moviegoers, but its loyalty amongst fans who enjoy an intense fright. And when it comes to it, Pulse is just a masterclass in creeping terror, with some of the most shocking, spine-chilling, and eerily unforgettable scenes in horror history. It may not get showered with praise as much as some of the other notable giants in the genre, but it's definitely a top contender that certainly deserves far more appreciation.

6 'Session 9' (2001)

One of the most shocking and twisted horror films of the early 2000s was Brad Anderson's Session 9, a psychological thriller from 2001 that has been steadily rising in popularity. This frightening concoction of mind-bending chills and slow-burning tension follows an asbestos cleanup crew at a decommissioned mental hospital as they slowly become terrorized by the dark secrets lurking within the building.

This truly mind-blowing film will leave anyone shaken up by its many shocking twists and stunning conclusion. By the end, Session 9 will have completely and utterly terrified you. It has you question what was real and how the filmmakers could have set up such storytelling tricks. It's a shame that Session 9 has become a hidden gem, perhaps due to its underwhelming impact upon initial release, but it's since garnered the attention it needed.

5 'Dog Soldiers' (2002)

From The Descent's Neil Marshall comes the criminally underrated masterpiece, Dog Soldiers, a werewolf action horror movie from 2002. This bloody, bullet-soaked thrill ride is an absolute blast from start to finish, featuring a pulse-pounding premise about a small group of British soldiers as their training exercise in the Scottish Highlands turns into a war against a pack of hungry lycanthropes.

It pits heavily armed soldiers against supernatural, nearly unstoppable beasts. Can this get any more thrilling? Dog Soldiers is a hidden gem that truly needs to be uncovered. It's got kick-ass fight scenes, epic shoot-outs, plenty of bloody violence, and the fascinating werewolf creature designs and gore that typically come with this type of movie.

4 'Strange Darling' (2024)

2024 was a year marked by horror excellence, with notable hits that are surely on their way to classic status. But one that certainly deserves it was Strange Darling, a tense, nonlinear crime thriller that's sure to leave viewers speechless. It's a twisted, unpredictable nailbiter about a deadly turn of events that happen when a mysterious young woman has a strange one-night stand with a supposedly dangerous man. But, as the story unfolds, it's revealed that this woman is not who she initially seems.

Strange Darling instantly hooks you in with an intense, suspenseful first half, then it shocks you by flipping the script and revealing an unexpected mid-act twist that completely changes the dynamic of the story and its characters. Having it told out of order helps to manipulate the viewer into believing the story is pretty straightforward, just so that it can pull the rug right from under them as the story progresses into what it's actually about. It truly deserves better attention, especially for what it evokes in the audience. It's definitely one of the most unpredictable horror films in recent years.

3 'The Ugly Stepsister' (2025)

2025 was truly the year defined by horror, featuring arguably one masterpiece after another. One of the year's greatest highlights, but also sadly one of its least talked about, was The Ugly Stepsister, a unique body horror period drama hailing from Norway. It's an eerie and tragic retelling of the classic story of Cinderella, following the perspective of the ugly stepsister, Elvira (Lea Myren), as she horrifically alters her appearance to achieve her fairy-tale ending.

It's dark, twisted, and full of the most disgusting imagery in recent horror. The Ugly Stepsister takes an iconic and world-renowned tale and adds a dark, twisted, and utterly heartbreaking spin to it, following a story of how beauty standards and family pressure can turn one's dreams into a horrifying nightmare. It's backed by excellent writing, beautiful sets, and gripping performances from its talented cast, all of which create an unforgettable horror experience that really needs better acclaim.

2 'Frailty' (2001)

From director and actor Bill Paxton comes one of the most suspenseful and shocking films of his glorious career, Frailty, a 2001 horror crime thriller that's full of startling terror. Also starring Academy Award winner Matthew McConaughey, it follows Paxton as a loving single father in the late 1970s who quickly becomes a notorious serial killer after claiming to see visions from God.

It's a film that constantly keeps viewers on their toes and holding their breath with suspense if they wonder is the main character is suffering a murderous breakdown or is really seeing signs from above. There are some unexpected turns and a shocking finale that's sure to leave your spine tingling at how startling it feels. Frailty initially underperformed both critically and at the box office, but rightfully earned its cult status in recent years and is now widely considered a masterpiece.

1 'Oddity' (2024)

Scaring its way to this top spot is Oddity, the 2024 underrated horror film by Damian McCarthy. A quietly intense, slow-burning, and masterfully successful thriller, it has the makings of an all-time great despite not being the biggest hit with audiences at the time. It follows a blind medium who dishes out a singular form of justice to her despicable brother-in-law for orchestrating her sister's death.

Arguably the scariest highlight of 2024, Oddity is a film that creeps under the skin and buries deep within, scaring viewers intensely from start to finish. It's full of shock and foreboding dread as we follow along in this spooky supernatural mystery, which only gets more twisted and eerie with every scene. How this was mostly swept under the rug upon initial release is baffling, as it's quite brilliant, expertly done, and undeniably terrifying, showing that it truly is a hidden-gem horror masterpiece.