Patrick Bateman in American Psycho chases a prostitute through an apartment building in New York City with a chainsaw while naked. The sequence may have been a figment of his deranged imagination. Not only does he kill her with the chainsaw, he drops it on her from several stories up and kills her. Ignoring the fact that most modern chainsaws have a safety on it so that if you let it go, it'll turn off. If you look closely you can see judicious use of Duct Tape.
In Army of the Dead, Vanderhoe carries a buzzsaw device around, which is useful to cut through both zombies and other materials (to open paths for the latter).
In Big Tits Zombie, the main character finds a chainsaw and is so overjoyed, she practically starts crying. The chainsaw even glows. This movie loves this trope so much that the first zombie kill, moments into the film, is a chainsaw attack.
Subverted in the horror-comedy Black Sheep (2007), in which Henry needs to perform half a dozen steps to get a complicated chainsaw's motor started, only to drop it over the side when the truck he's riding goes over a bump in the field.
Blood Pi: When Professor Milbern is handcuffed to the ceiling of Omega Pi's basement, Amber comes down and uses a chainsaw to castrate him.
Ed Gein picks up a chainsaw and uses it to drive off the Zodiac Killer in The Butchers.
As the cast of Children of the Corn V: Fields of Terror become besieged in a barn, Tyrus picks up a chainsaw. After he is killed, one of the children pick it up and start chasing Allison with it.
Dark of the Sun, based on the Wilbur Smith novel, features two men in a chainsaw duel.
Dawn of the Dead (2004): Painfully subverted during a high-speed zombie car chase. One of the characters accidentally loses his grasp of the chainsaw, which cuts into another survivor. This causes their getaway truck to topple over.
In Deranged (2012), Final Girl Silvia finds a chainsaw in the garden shed and uses it to take on the axe-wielding killer in their final confrontation.
Das deutsche Kettensägenmassaker by Christoph Schlingensief, a political satire on the reunification of Germany, is a nod to the Texas original already in the title.
InEvil Aliens, a combine harvester is a drivable chainsaw.
Ash Williams from the Evil Dead films. This is a badass guy who cut off his own demon-possessed hand and replaced it with a chainsaw mounting. Obviously not to be taken lightly. He still has it in Army of Darkness, but soon replaces it with a mechanical hand that he just invented because why not.
The space monster Gigan, first introduced in Godzilla vs. Gigan, qualifies for the buzzsaw variant of this trope thanks to his rotating cutter that runs down his chest, and he puts it to great use in battle against Godzilla and Anguirus, including a particularly brutal moment where Anguirus makes the mistake of charging him while he has it running, getting his face sliced for his trouble. This is taken further in Godzilla: Final Wars, where Gigan eventually receives a pair of double-pronged chainsaws instead of hands. And before the chainsaws for hands, he had hooks for hands. Gigan can even use these chainsaws like rudimentary tank tracks, jamming the ends into the ground and using them to accelerate forward at quite impressive speeds.
In Gremlins, Stripe uses a (small) chainsaw from the hardware store to attack the human hero, who fends off the blade with a rapidly-fragmenting wooden baseball bat. Bonus points for awesomeness in that we hear the chainsaw's motor revving up, just before Stripe attacks, and can guess what the little creep just got his scaly hands on.
Halloween: Resurrection. Sarah gets a few good swings in before it stops working (which is probably justified, since she found it among the junk in the Myers' abandoned garage) prompting her into throwing it at Michael.
In The Hazing, Justine bursts into the bedroom where Delia and Roy are having sex wielding a running chainsaw in an attempt to scare them. However, as Dela is currently being strangled by Roy's detached Overly-Long Tongue, it does not have the desired effect. Roy grabs the chainsaw off her and uses it to kill the tongue.
Helldriver give us chainsaw-wielding zombies... so of course the heroine takes them down with a chainsaw katana.
Hell's Highway: When the video ends, Lucindia appears, and attacks and mortally wounds Chris with a chainsaw.
High Tension: Both the killer and the protagonist get a turn with a circular saw.
The first Hostel. Boy, did that backfire. The sequel has a circular saw.
Hot Bot: When he thinks that Bardot is a zombie, Nard arrives at Huffy's house with a chainsaw to destroy her. Becomes a Chekhov's Gun when he uses it to escape from the trunk of his car.
A Chainsaw arm shows up in The Machine Girl alongside a Machine Gun one.
Mad Max: Beyond Thunderdome. During the Thunderdome fight, Max snatches a chainsaw to fight Blaster, but struggles to get it working. After it finally catches, it runs out of fuel before he can even swing it. Fuel is the most precious commodity, after all.
In its continuation Mad Max: Fury Road, multiple War Boys try to cleave the heroes with chainsaws (although they end up killing other War Boys instead thanks to some Deadly Dodging). The one War Boy that manages to fatally wound a hero is a downplayed example, cutting the Keeper of the Seeds' jugular with an arm-mounted hedge trimmer.
In a case of a victim using a chainsaw against the killer occurs in Maniac Cop 2, where the heroine of the previous entry is thrown through the window of a hardware store by Officer Cordell. Grabbing a chainsaw, she tries to attack him with it but he just nonchalantly grabs the blade, wrenches it from her grasp and snaps her neck.
In Mandy (2018), Red uses a long chainsaw to attack one of Jeremiah Sand's cultists, who pulls out one of his own that is nearly twice as long, allowing them to duel with chainsaws. But as awesome as a duel with chainsaws is, the film also shows how impractical they are as weapons.
In the final battle of The Marine, Rome attacks Triton with one. Triton defends himself with a wrench, which gets sawed in half, but manages to force Roman to drop the chainsaw.
In Monster Party, Patrick hands Cameron a chainsaw when they go hunting Casper and Alexis. Cameron's eyes light up with a manic glee as he revs the engine.
Motel Hell ends with a chainsaw duel between a sheriff and a crazed farmer wearing a pig's head as a mask.
In Mr. Mom, Jack Butler's first meeting with his wife Caroline's boss Ron Richardson is when he is wielding a chainsaw and coming into the house with it still running. Played mostly for laughs as Jack makes it look like he's just using it for remodeling the house, though after Ron leaves Jack contemplates using it for "trimming" Ron's mustache.
Subverted in Mr. Nice Guy, when a Mook swings a big circular grinder at Jackie, but it comes unplugged the instant the thug tries to chase him with it.
When G-Girl reveals her secret identity to Matt in My Super Ex-Girlfriend she makes him swear that he would rather have a chainsaw shoved up his ass than tell. When Matt imagines he tells his friend, she brandishes a chainsaw telling him he was warned.
My Name is Bruce references Ash's signature chainsaw. When a rabid fan offers Bruce Campbell a chainsaw modeled on Evil Dead to fight an unleashed god, Bruce is honored but turns it down because it's too damn heavy and unwieldy to use in combat.
The killer in Pieces uses a chainsaw to cut up his victims and collect the bodyparts that he desire for his project.
In the fourth Police Academy movie, Tackleberry scares off a few new recruits to the Citizens on Patrol program with a chainsaw — specifically by cutting his way out of a body bag.
When the Freeling family are escaping their house and get in their car in Poltergeist II: The Other Side, a possessed flying chainsaw tries to stop them.
Pulp Fiction: When Butch is choosing a weapon to use to rescue his enemy Marsellus Wallace, the chainsaw is in the middle of his weapon escalation. He tosses aside a hammer to take the chainsaw, then tosses the chainsaw to grab a katana. Swords are easier to sneak up on people with, after all.
Robot Jox gives us a chainsaw on the Big Bad's robot. Its placement on the robot's torso is near crotch-level.
Royal Warriors have the last villain, Bull, using a chainsaw to attack the heroine Michelle (played by Michelle Yeoh). After several close shaves, Michelle managed to trick bull into shoving the saw into some plants, where he gets Left Stuck After Attack and Michelle gets some kicks in.
Buzzsaw from The Running Man. He even mounts his chainsaw to his motorcycle.
In Savaged, Trey chooses to wield a chainsaw as his weapon in his final showdown against the Revenant Zombie Zoe.
The Saw series seems to prefer circular saws to chainsaws.
Scarred: Naturally, a chainsaw would be amongst Jonah Kandie's murder implements. One notable scene has him killing Shawn while he's stuck in a wall.
This is Fin's weapon of choice in the climax of Sharknado. It was so effective then that in Sharknado 2: The Second One, he actively seeks some out even earlier in the film after being informed that gun stores are illegal in New York. The sequel also features one old guy who revs up a bunch of chainsaws before hurling them into the wind to chop up the sharks on their own. In Sharknado 3: Oh Hell No!, Fin receives as an award a fully functional gold-plated chainsaw. April's artificial hand can be swapped out for a chainsaw, and in the climax, Fin gets a lightsaber chainsaw.
Shredder Orpheus has the Furies bind and decapitate Orpheus with a hedge trimmer after he fails the rigged game show.
Slashers: As indicated by his name, Chainsaw Charlie uses a chainsaw as his weapon.
In the 2007 movie Smokin' Aces, one of the Tremor brothers uses a hand-mounted chainsaw during their assault on the Nomad Hotel, with predictably devastating results.
Stacy, a Japanese movie concerning zombie schoolgirls (or "Stacies") who only seek love and acceptance from the living (despite eating many of them), reveals that the only way to destroy a Stacy is via "repeat-killing," specifically dismemberment. To facilitate this, one can purchase "Bruce Campbell's Right Hand," a chainsaw that fits over the user's right hand. It comes in several different colors, many of them new this season!
The killer in StageFright -Aquarius- manages to kill one victim with a chainsaw until it runs out of fuel.
Art for Transformers: Dark of the Moon showed that one of the options for Optimus Prime's weapons pack — an option which was not used in the final film — included a giant, triple-chained chainsword.
The Tripper: As a child, Gus used a chainsaw to murder the protestor who struck his father. The killer scores his last kill of the film with one.
In Vampires vs. Zombies, Travis uses a hedge trimmer (although he calls it a chainsaw) to wipe out the pack of zombie schoolgirls attacking Jenna.
In Very Bad Things, Boyd uses a chainsaw to cut up the two bodies in the hotel bathroom.
In The Video Dead, a character manages to put most of the eponymous undead into pieces with a chainsaw. The remaining one snatches the thing, and eventually manages to impale him with it.
Voyage of the Rock Aliens: The aptly-named Chainsaw spends most of the movie killing people, but he does have a heroic moment towards the end, when he fights off the tentacle monster attacking Dee Dee and Frankie.
Aiko, one of the heroines in the Japanese comedy/horror flick X-Cross uses a rather conveniently placed chainsaw at one point to fight an insane, giant-pair-of-scissors-wieldingGoth Lolita named Reika. Unfortunately, this fails, as she winds up dropping it. She ultimately resorts to torching Reika. Which also fails.
In Zombies! Zombies! Zombies!, Dallas grabs the chainsaw from the back of Chris's truck and uses it to fight her way through the zombies in the car park.
that it was an homage to Evil Dead and The Texas Chainsaw Massacre.