This article lists the various background character deaths that occur in Avengers: Age of Ultron.
- Two HYDRA agents are killed by stray shots from other HYDRA soldiers that are chasing Hawkeye and Black Widow.
- Thor beats up two HYDRA troops on a Humvee and five more atop a guard tower. It is unclear if the soldiers are killed or simply knocked out.
- Thor knocks a HYDRA jet-pack trooper out of the sky before beating down three on the ground with a metal girder.
- While riding his motorcycle, Captain America grabs a HYDRA soldier and drags him across the ground before single-handedly throwing him into another soldier.
- Cap throws his shield at one HYDRA soldier then catches it as he takes down another with a wheelie on his bike.
- Thor destroys a HYDRA armoured truck by flying straight into it.
- The Hulk grabs two HYDRA jet troopers out of the air and bashes their heads together before throwing them at a group of soldiers on the ground.
- A HYDRA soldier gets thrown against a tree.
- Thor drops down from the sky right on top of a HYDRA trooper, then takes down three more with Mjolnir.
- Black Widow throws a grenade onto a HYDRA truck and blows it up. One of the soldiers gets clear of the blast but then gets kicked to the ground.
- Romanoff uses her acrobatic skills to wheel around on the shoulders of two HYDRA agents that are close together and breaks their necks.
- Romanoff uses a Glock to shoot a HYDRA soldier manning a machine gun turret.
- Hawkeye uses an explosive arrow to destroy a HYDRA plasma cannon and kill its gunner.
- Iron Man flies over Baron Strucker's base and blasts six HYDRA troops on a stairway with his repulsor beams.
- Cap jumps off of his motorcycle and picks the whole bike up by the handles, lifting it overhead and hurling it at an oncoming HYDRA truck where it explodes on impact. It is unclear how many HYDRA soldiers were killed.
- After Hawkeye gets hit by a plasma beam fired from a small bunker, Black Widow calls for Hulk to take care of it. Hulk charges straight into the bunker and demolishes it, most likely killing the gunner inside.
- Cap takes down two HYDRA soldiers by throwing his shield, then punches out three more. It is unclear if the soldiers are killed or merely knocked out.
- A pair of HYDRA soldiers manage to land a shot on Iron Man. Upon being hit, Iron Man lands and takes out the two soldiers with his repulsors.
- Iron Man rockets through the courtyard of the HYDRA research base, shooting at least five soldiers on the way.
- Thor strikes the ground with Mjolnir, creating a shockwave that takes out a group of HYDRA troops that are attempting to flee.
- About ten HYDRA troops and a tank advance on Captain America and Thor. Thor strikes Cap's shield with Mjolnir and creates a shockwave that bowls over the line of soldiers and rips off the tank's turret.
- After taking down the base's shields, Iron Man enters by crashing through a window, knocking three soldiers off a platform.
- Shortly after his "birth", Ultron seizes control of Stark's Iron Legionnaire robots and has them attack the Avengers in Stark Tower. Thor uses Mjolnir to destroy one that lunges at him.
- Thor tears one of the Iron Legionnaires in half, but the top half remains active and closes in on Dr. Helen Cho. Rogers grabs the bisected Legionnaire and throws it back to Thor who smashes it.
- Tony jumps on the back of an airborne Legionnaire and uses a screwdriver to loosen a key circuit in the robot's neck, causing it to shut down.
- Cap smashes the fourth Legionnaire to bits after throwing his shield at it.
- Thor throws Mjolnir at the damaged Iron Legionnaire that Ultron's consciousness is occupying, smashing it to pieces. However, Ultron's AI has already spread via the internet to the abandoned HYDRA base in Sokovia where it takes control of the machine shops and begins building its army of Ultron Sentries.
- Maria Hill updates Rogers on Ultron's activities, explaining that he's seized control of robotics labs and hi-tech facilities around the globe. Hill confirms that people have died after attempting to attack the Sub-Ultron robots, but gives no estimate on fatality numbers.
- Hawkeye shoots at least one of Ulysses Klaue's thugs during the Avengers' confrontation with Ultron in South Africa.
- Cap immobilises an Ultron Sentry long enough for Thor to take its head off with a hammer strike.
- Hawkeye uses a sonic arrow to take out four of Klaue's men at once.
- After falling victim to Scarlet Witch's psionic abilities, Natasha experiences a flashback of her training in the Red Room. In this flashback, she shoots a captive man with a sack over his head.
- Iron Man pursues Ultron and shoots him down, but the malevolent robot cryptically states that he is in multiple places at once and the loss of one body doesn't matter. Iron Man then blows up Ultron's first body with a rocket before going to find Dr. Banner.
- Under Wanda's spell, Hulk goes on a rampage in Johannesburg. It is unknown how many people, if any, he kills before Iron Man arrives to stop him.
- It is unknown how many innocent bystanders are killed during the battle between Hulk and Iron Man's Hulkbuster armour, though it is highly improbable that there wouldn't be fatalities.
- When Dr. Cho tries to interrupt Ultron's upload into his new synthezoid body, Ultron's drones react and shoot Cho and her assistants. Cho survives, but her assistants do not.
- During the chase through Seoul, Ultron uses his gravity field generator to cause three cars to crash. It is unknown if the drivers are killed or not.
- The Sub-Ultron unit driving the truck from Cho's lab is destroyed when the Sub-Ultrons protecting the Regeneration Cradle lift the truck's trailer up into the sky, causing the truck to crash.
- Ultron escapes from a moving train, killing the conductor with his concussive energy beams.
- Ultron destroys his second body using his third, ultimate body made from vibranium. As he is talking to a captive Natasha with his second body, his third body thrusts a fist through his second body's head.
- As the Battle of Sokovia begins, Hawkeye shoots an Ultron Sentry and stabs one in the head when it creeps up behind him.
- Hawkeye fires an explosive arrow at an Ultron Sentry flying above a bridge.
- Captain America smashes a Sub-Ultron over the hood of a car.
- Thor smashes four Ultron Sentries inside a chasm.
- Quicksilver destroys five Ultron Drones by charging right through them.
- Cap grabs an Ultron Drone and smashes its head against a bridge support girder.
- While Ultron is monologuing through all of his sub-units, Hawkeye shoots one out of the air and Cap punches in the faceplate of another.
- Quicksilver rushes through the streets of Sokovia and smashes six Sub-Ultrons in his path.
- As Ultron's robots start firing on civilians, the Hulk leaps into the scene and lands on one of the drones before tearing it apart.
- Hawkeye shoots down a flying Ultron Sentry targeting civilians.
- Scarlet Witch brings up a telekinetic barrier and knocks an Ultron Sentry out of the air, causing it to crash in a fiery explosion.
- Hawkeye leaps off of a car and shoots an Ultron Drone in the back of the head.
- Hawkeye gives Wanda a pep talk while the two of them take cover in a building. An Ultron Drone outside fires at the building, leaving a hole in the wall close to Hawkeye. He fires an arrow through the wall and the sound of clanging metal confirms that he hit his target.
- Cap swings a steel girder at an Ultron Drone that lunges at him.
- Another Sub-Ultron charges at Cap who is standing at the edge of the flying landmass. Through the drone, Ultron states that the Avengers won't be able to save everyone, but Cap interrupts Ultron's tirade by throwing his shield into the drone's chest, then throwing the damaged robot over the cliff.
- Black Widow takes down a Sub-Ultron with her electrified eskrima sticks.
- Cap throws up his shield and Thor bats it with Mjolnir, sending it flying and slicing through several Sub-Ultrons.
- Thor uppercuts an Ultron Drone into the air, then throws it at a gas tanker. Several more Ultron Drones are destroyed by the explosion.
- Hawkeye blows up an Ultron Drone with an explosive arrow.
- Wanda grasps an Ultron Drone with her telekinesis, causing it to fire its weapon at another drone before ripping it in half. She then throws the torso of that drone into another, smashing both to bits.
- Hawkeye fires two arrows at once, striking a pair of Ultron Sentries in the head.
- Wanda launches a blast of psychokinetic energy that disintegrates three Ultron Sentries.
- Cap cuts the head and shoulders off an Ultron Drone with his shield.
- Wanda fires another psionic blast that tears through three Ultron Sentries.
- Cap and Black Widow tag team to destroy three more Sentries.
- When Nick Fury arrives with a Helicarrier to evacuate Sokovia's citizens, War Machine and Falcon enter the fray. War Machine starts by shooting down four Ultron Sentries.
- Iron Man backs up War Machine by blasting an Ultron Sentry that's chasing him.
- Iron Man shoots two more Ultron Drones out of the sky.
- One of Ultron's sub-units makes a suicide run at the Helicarrier, smashing into the bridge. The damaged robot crawls out of the wreckage of Fury's conference table and is then terminated when Fury stabs it through the head with a sharp metal fragment.
- Iron Man shoots down a few more Ultron Sentries attacking the Helicarrier.
- War Machine grabs a Sub-Ultron in flight with his legs then shoots its head off with his shoulder-mounted Gatling gun.
- Romanoff runs over several Ultron Sentries with a bulldozer.
- Hulk lands on an Ultron Drone and smashes another beside him.
- The Avengers unite around the vibranium detonator and, in a spectacular battle royale, annihilate the majority of Ultron's remaining drones.
- War Machine and Vision destroy seven Ultron Drones that attempt to flee from Novi Grad.
- Wanda and Pietro each destroy an Ultron Drone while arguing with each other.
- Romanoff goes to rendezvous with Hulk and finds him ripping an Ultron Drone in half.
- A Sokovian police officer is killed when Ultron hijacks the Avengers' Quinjet and starts opening fire on the streets.
- After Pietro is killed, Wanda can feel her brother's passing and cries out in anguish. At the same time, she releases a massive blast of energy that disintegrates seven Ultron Sentries lunging at her from all sides.
- A critically damaged Ultron Drone crawls over to the vibranium detonator and hits its main switch, causing Novi Grad to drop out of the sky. The drone powers down as it hits the switch.
- Iron Man and Thor detonate the core of Ultron's vibranium generator, causing the airborne landmass carrying Novi Grad to explode. By then, all of the citizens have been evacuated and the explosion vaporises any Ultron sub-units remaining, save for one.
- Vision meets with Ultron one last time who is inhabiting the heavily damaged body of his last remaining drone. After a brief exchange regarding human behaviour, the drone lunges at Vision who vaporises it with a blast of energy from the Mind Stone in his head. With this act, Ultron is completely destroyed.