Thanos is a fictional character portrayed primarily by Josh Brolin in the Marvel Cinematic Universe (MCU) media franchise, based on the Marvel Comics supervillain of the same name. He is depicted as an alien warlord from the doomed planet Titan with a universe-spanning agenda to wipe out half of all life to stabilize overpopulation and prevent what he views as life's inevitable extinction.
To do this, he sets out to obtain the six Infinity Stones, cosmic gems with the power to achieve his goal. With the help of his adopted children, Thanos fights against the Avengers, the Guardians of the Galaxy, and their allies, in the Infinity War, succeeds in assembling the Stones, and disintegrates half of all life in the universe in an event that is known as the Decimation. After escaping to the Garden and destroying the Stones, he is found and confronted by the surviving Avengers, and promptly killed by Thor once he reveals that his act is irreversible. Five years later, an alternate version of Thanos from 2014 time travels to 2023 to battle the Avengers once again, but is killed by Tony Stark.
Thanos is a key figure in the 23 films that make up the MCU's Infinity Saga, having appeared in five of its films, most notably as the main antagonist of both Avengers: Infinity War (2018) and Avengers: Endgame (2019). Several versions of Thanos from alternate realities in the MCU multiverse also appear in Endgame, the Disney+ animated television series What If...? (2021–2024) and Marvel Zombies (2025), and the Phase Four film Doctor Strange in the Multiverse of Madness (2022).
Thanos' appearance changed drastically over the course of his appearances as advances in CGI and motion capture technology allowed for better capture of Brolin's facial features. A new facial capture application called Masquerade was created for Infinity War and Endgame using machine learning. The character has been praised by critics and fans alike, with Brolin winning multiple awards for his performance. Thanos is often credited as one of the MCU's best villains, as well as one of the greatest film villains of all time. After his appearance in Infinity War, he became a key figure in popular culture and memes, making appearances in a variety of other media.
Fictional character biography Thanos' story in the MCU takes place in the Earth-616 universe. The fictional biography below includes events that happened to Thanos from more than one Earth-616 timeline, as well as events that happened to him from multiple other universes.
Early life Thanos was born approximately 1,000 years ago on the planet Titan to A'Lars, along with his brother Eros. Thanos deems the growth of Titan's population to be unsustainable, so he proposes to arbitrarily kill half of Titan's population. However, his people reject the idea and Thanos is subsequently ostracized. Over time, Thanos' prediction comes to pass, with him and Eros being the only surviving members.
Balancing the universe Thanos, driven by his belief that the universe must be balanced by eliminating half of its population, embarks on conquests involving the killing of half of the planets' populations, becoming feared and powerful while taking control of various armies. He forges alliances with the Other and Ronan the Accuser, and adopts orphan children from worlds he invades, including Gamora and Nebula, considering the former to be his favorite. Eventually, he decides to obtain the Infinity Stones after realizing he could use them to wipe out half of all life in the universe. He obtains the Mind Stone and places it in a scepter.
In 2012, Thanos directs the Other to form an alliance with Loki. Thanos provides Loki with the scepter and a Chitauri army to obtain the Space Stone within the Tesseract by conquering Earth. Following Loki's defeat by the Avengers and the loss of the Mind Stone, the Other reports the failed attack to Thanos. In 2014, Thanos locates the Power Stone and sends Ronan, Gamora, and Nebula to retrieve it. However, they betray him: Gamora joins the Guardians of the Galaxy, Ronan obtains the Power Stone and resolves to kill Thanos after destroying Xandar, while Nebula allies with Ronan. The Guardians of the Galaxy defeat Ronan and leave the Power Stone with the Nova Corps. In 2015, Thanos arrives on Nidavellir and forces the native Dwarves to forge the Infinity Gauntlet to hold all six Stones, planning to collect them himself.
The Blip and death In 2018, Thanos and his children decimate Xandar to retrieve the Power Stone. Shortly after, they intercept a ship carrying Asgardian refugees following their world's destruction. Thanos kills half of them and incapacitates Thor. Loki attempts to exchange the Tesseract to save Thor, but betrays Thanos and is killed. Thanos then defeats the Hulk after being attacked by him, and obtains the Space Stone from the Tesseract. He orders his children to retrieve the Mind Stone and Time Stone from Earth before convening on Titan.
Thanos travels to Knowhere and obtains the Reality Stone from Taneleer Tivan. The Guardians of the Galaxy arrive to stop him, but Thanos uses the Stone to defeat them and captures Gamora. Forcing her to reveal the location of the Soul Stone, they travel to Vormir, where the Soul Stone's keeper, Johann Schmidt, informs them that the Soul Stone requires the sacrifice of a loved one. Thanos then tearfully sacrifices Gamora to obtain the Stone.
Arriving on Titan expecting to meet with one of his children, Thanos encounters Stephen Strange and learns his child is dead. Ambushed by Tony Stark, Peter Parker, and members of the Guardians of the Galaxy, a fight ensues. Thanos is briefly incapacitated by their efforts as they attempt to remove the Infinity Gauntlet. However, once Peter Quill learns Thanos killed Gamora, he attacks Thanos in a fit of rage, causing him to break free and overpower them. He then prepares to kill Stark, until Strange offers the Time Stone in exchange for sparing Stark's life.
Thanos then teleports to Wakanda on Earth and encounters resistance from the Avengers - Bruce Banner, Steve Rogers, Sam Wilson, James Rhodes, Natasha Romanoff, Bucky Barnes, T'Challa, and Groot. After quickly defeating them, Thanos makes his way to Vision but Wanda Maximoff destroys the Mind Stone. However, Thanos uses the Time Stone to undo it and gains the Mind Stone, killing Vision. Placing it in his Gauntlet, Thanos is in possession of all six Stones. However, Thanos is impaled in the chest by Thor's axe, Stormbreaker. Despite his pain, Thanos manages to snap his fingers, successfully decimating half of all life in the universe.
With his mission complete, he teleports to the Garden, where he rests. Twenty-three days later, Thanos is ambushed by surviving members of the Avengers, Rocket Raccoon, Nebula, and Carol Danvers. They intend to use the Stones to reverse the snap, only to learn Thanos anticipated this and destroyed the Stones to prevent their further use. Enraged, Thor decapitates Thanos.
Battle at the Avengers Compound In 2023, the surviving members of the Blip plan to use the Quantum Realm to time travel in order to retrieve the Stones. 2014-Thanos becomes aware of the Blip after the cybernetic implants of 2014-Nebula link to 2023-Nebula, revealing the latter's memories. Thanos has 2014-Nebula impersonate her future self and travel to 2023 so she can use the Quantum Realm to transport Thanos and his army there.
2014-Thanos arrives within his warship and destroys the Avengers Compound. While his army searches for the Stones, Thanos engages in a fight with Stark, Rogers, and Thor, during which he decides to destroy all life and repopulate it so that life would be grateful. Thanos defeats Stark and Thor, leaving only Rogers. He calls forth his armies, but the Avengers' restored allies arrive and engage Thanos and his army in a final battle. Thanos is nearly killed by Maximoff and orders his warship to rain down missiles to save him. Thanos defeats Danvers, Rogers, Thor, and Stark. After a struggle, Thanos obtains the Stark Nano Gauntlet, but Stark tricks Thanos by removing the stones and attaching them to his suit. Stark then snaps his fingers, turning Thanos and his entire army to dust, at the cost of his own life.
Legacy within Earth-616 Thanos's actions have a universal impact, with the surviving Avengers working to mitigate the damage until they undo the Blip five years later in 2023. Maximoff is traumatized by Vision's death, causing her to have a mental breakdown and create a false reality.
Ajak, leader of the Eternals, informs Ikaris that the Blip delayed an apocalyptic event called the Emergence, saving many planets from destruction. However, when the Avengers reversed the Blip, the Emergence continued. Ajak feels the Earth should be saved and recruited the Eternals to stop the Emergence, doing so successfully.
The sudden return of the population has an impact as well, with the Global Repatriation Council (GRC) working to reintegrate the Blipped population. It led to socioeconomic conflicts, with entities like the Flag Smashers believing Thanos' ideas were correct. Feeling life was better during the Blip, they use terrorism against the GRC as they felt the GRC favored Blipped people more than the survivors. Moreover, the phrase "Thanos was right" is observed in popular human culture, being used in graffiti and merchandise for profit.
Alternate versions Multiple versions of Thanos are depicted in alternate realities of the MCU multiverse.
Joining the Ravagers
In an alternate reality, Star-Lord T'Challa convinces Thanos to join the Ravagers by persuading him there are other ways to preserve resources. In 2008, Thanos participates in their mission against the Collector, where he fights against his former allies, the Black Order. Thanos struggles in the fight, but Nebula helps him, and together they defeat his forces.
Zombie Outbreak
In an alternate 2018, Thanos arrives on Earth in Wakanda with a nearly complete Infinity Gauntlet, but is infected by a quantum virus and transforms into a zombie. Infected Thanos gradually starts learning to use the stones amidst the fight with Spider-Man, Scott Lang and T'Challa and acquires the last Infinity Stone, the Mind Stone, from them to complete his gauntlet. He is defeated by T'Challa, who also sacrifices himself by lunging at him and plunging them both into Wakanda's vibranium core, destroying the Infinity Stones and releasing a surge of energy.
Other universes In another alternate universe, Thanos arrives on Earth to retrieve the Mind Stone after collecting the other Infinity Stones, but is swiftly killed by Ultron. In a separate reality, Thanos is killed by Gamora who claims his warlord position, armor, and blade. Thanos had sent Gamora after Tony Stark following the Battle of New York, but Stark convinced Gamora to turn on her father and aided her in killing him. On Earth-838, Thanos is killed on Titan by the Illuminati, who use the Book of Vishanti to impale him with his own double-sided sword. In another alternate universe, Thanos is killed with Gamora by Ronan the Accuser, and Nebula escapes from his shadow and joins the Nova Corps. In another alternate universe, as Thanos approaches a young Gamora, Hela arrives with the armies of Asgard and the Ten Rings to stop him. In an alternate 2018, Thanos went on his quest to obtain the Infinity Stones. When he arrived in Wakanda, he was confronted by Steve Rogers and engaged in a fight. However, Rogers hit his shield against the Time Stone, which transported him elsewhere. An alternate version of Thanos was imprisoned by Doctor Strange Supreme to be sacrificed to his Forge. Released by Captain Carter, Thanos attacked her and Kahhori only to be disintegrated by Infinity Killmonger with his own set of Infinity Stones.