G Corporation is a cutting-edge biotech firm making revolutionary advances in the field of bio-genetics research in the Tekken series.
After Kazuya Mishima killed all its high executives and assumed control, however, the company shifted more towards military development in order to compete against the Mishima Zaibatsu after Jin's declaration of war on the world. Its main headquarters is its Millenium Tower.
G Corporation accidentally stumbled upon the remains of Kazuya Mishima, who had been thrown into a volcano by his father, Heihachi Mishima, after Kazuya was defeated in The King of Iron Fist Tournament 2. This happened during a routine research mission at Mt. Shirane. Afterwards, Kazuya's body was taken to the G Corporation’s Nebraska research facility.
After being resurrected, Kazuya offered his body as research material for genetic experimentation to investigate, determine, and harness the true mechanism of the Devil that resided within his body.
G Corporation raid
Heihachi Mishima discovered that G Corporation had found the remains of Kazuya, and had extracted and analyzed the genetic data. In fact, Heihachi learned that the G Corporation was in the midst of creating a new life form by using the data. Heihachi himself had intentions of creating the ultimate life form by combining Ogre's DNA with his, but he needed the Devil Gene, something of which only his son, Kazuya, and his grandson, Jin Kazama, possessed.
Heihachi used the Tekken Force to raid G Corporation’s maximum security research laboratory in Nepal on December 25. The bottom floors of the building were completely destroyed. The remaining data storage facility containing file servers was airlifted by a group of heavy-duty helicopters. At the same time, a separate unit, which was led by Heihachi himself, infiltrated the G Corporation underground research facility in Nebraska, where Kazuya Mishima’s remains were supposedly preserved. The operation in Nebraska failed, due to the unexpected intervention of Kazuya Mishima.
Before The King of Iron Fist Tournament 5, many Jack-4s were sent to attack Heihachi and Kazuya at Hon-Maru. Kazuya escaped before one of the Jack-4s self-destructed by transforming into Devil (or Devil Kazuya, which is what Devil is called in Kazuya's Tekken 5 prologue) and flying away through a hole in the wall. Heihachi did not escape, as Kazuya threw him to the Jack-4s before making his escape. The explosion almost killed Heihachi, but he managed to survive. This is most likely revenge for the raids on G Corporation in Nepal and Nebraska.
Kazuya, who was caught up with G Corporation's attack on Hon-Maru, believed that the executives of G Corporation plotted against him as well. At the conclusion of the King of Iron Fist Tournament 5, he killed all the executives of G Corporation that betrayed him before taking the company for himself. Shortly Kazuya's takeover, Jin declared the Mishima Zaibatsu's independence and waged war against the world
Unable to accept a world ruled by someone other than himself, Kazuya publicly announced G Corporation's decision to fight the Zaibatsu and was celebrated as a hero. Recruiting his previous subordinates, Anna Williams and Bruce Irvin, Kazuya released a large bounty on Jin's head, who responded by announcing the King of Iron Fist Tournament 6.
War Against Heihachi
Near the end of the sixth tournament, Jin mysteriously disappeared. Without its leader, the Mishima Zaibatsu began losing progressively against G Corporation until the arrival of Heihachi, who took control of the company from Nina Williams. The company then attempted to attack Heihachi, who was held up in a fight against Akuma, the man sent by the late Kazumi to kill Kazuya and Heihachi, with a squadron of Jack-6s. Although the entire unit was destroyed, their camera footage gives more information about Akuma, who eventually defeats Heihachi.
With Heihachi declared dead, and the King of Iron Fist Tournament 7 suspended, Akuma arrives at the Millenium Tower to fight Kazuya. After a brief fight by the two, Kazuya is forced to use his Devil Gene to keep up, but Heihachi, who faked his death, proceeds to broadcast the fight's footage to the world, declaring Kazuya to be a demon in a man's body. Heihachi then destroys most of the Millenium Tower by using a satellite laser, taking out both Akuma and Kazuya.
Kazuya, however, survives the blast, and, in retaliation, Kazuya destroys the space station and pinned the blame of the disaster on the Zaibatsu.
Eventually, Heihachi invites Kazuya to a final duel to the death within a volcano. Ultimately, Kazuya emerges victorious, and G Corporation scores a massive blow over the Zaibatsu after Kazuya flings the unconscious Heihachi with the volcano.
The physicist Jane was protected by Gun Jack when the Tekken Force attacked her inside Mishima Zaibatsu Heavy Industries. A G Corporation freighter saved her the next day. She became an engineer for G Corporation, developing Jack-4, as well as Jack-5, Jack-4's successor. G Corporation sent Jack-5 to The King of Iron Fist Tournament 5 for field testing. After Jack-5's memories are restored, she creates the sixth model which is Jack-6 after being demanded about making another JACK model after Jack-5. G Corporation sent Jack-6 to The King of Iron Fist Tournament 6 to stop against the Mishima Zaibatsu, In ‘’Street Fighter X Tekken’’, it is implied that Jane has been spying on Ryu, a character from the ‘’Street Fighter’’ series and UDON Comics to gain information on the Satsui no Hado, thought Kazuya is not aware of this.
In the events of Tekken 7, Jane and her team are revealed to be in competition with another research team, which is developing the new biotechnological weapon named Gigas. Both teams entered their weapons into the King of Iron Fist Tournament to decide once and for all which was the best.
- Kazuya Mishima - CEO since Tekken 6.
- Jane - A scientist in G Corporation Heavy Industries.
- Julia Chang - A researcher in G Corporation Biotech, secretly allied with Lee, Lars and Alisa to plan a coup d'etat during Kazuya's leadership.
- Emma Kliesen - G Corporation executive. Was killed with other executives during Kazuya's takeover.
- Anna Williams - Kazuya's assistant and secretary.
- Bruce Irvin - Kazuya's army leader.
- Ling Xiaoyu - Hired by Anna in Blood Vengeance to gather information about Shin Kamiya, she later betrays the company because of her unwillingness to get herself involved with the Mishima clan's feud (non-canon).
- Lucky Chloe - An idol sponsored by the company.
- Jack series - A series of robotic soldiers developed under Jane beginning with Jack-4.
- Gigas - A new type of biological super soldier developed by the Bio Research division by experimenting on the foster father of Katarina Alves.
G Corporation has a large military that is capable of holding its own against the Zaibatsu. They have armoured cars, tanks, rocket artillery, and a range of support and attack helicopters. A number of different kinds of G-Corp soldiers are known to exist:
- G-Corp Trooper - equipped with light armor and SG553 assault rifles.
- G-Corp Heavy Trooper - equipped with heavy armor and a M134 minigun.
- G-Corp Special Forces - equipped with camo armor and ACR assault rifles.
- G-Corp Security Guards - usually in suits with no armor, equipped with MP7 submachine guns.
- Jack series
- Although never seen, G Corporation performs animal experimentation. 
- Millenium Tower is equipped radio wave emitters to ward off pests and rodents 
- Lightning Storm (Tekken 6/Bloodline Rebellion)
- G Corp. Helipad (Tekken 7/Fated Retribution)
- G Corp. Helipad (Night) (Tekken 7/Fated Retribution)
- G Corporation, Millennium Tower (Tekken 6/Bloodline Rebellion) (Scenario Mode only)