This is a list of characters from the Guilty Gear fighting game series.

Daisuke Ishiwatari has cited Kazushi Hagiwara's manga Bastard!!, and the fighting game Street Fighter II as influence to the Guilty Gear series. However, he noted that the majority of other fighting games were just recycling the character's same skins or style, and so he wanted every character "to be unique in their own way." Kazuhiko Shimamoto's characters were also noted as an inspiration for the male characters, with Ishiwatari saying they needed to be "chivalrous person-like characters", and citing Anji Mito "the most closest to this type". The female ones, on the other hand, have not followed a standard, with Ishiwatari only remarking that they needed to look like real women.

There are many musical references in the Guilty Gear series, including various characters' names and moves, which were inspired by rock and heavy metal bands like Queen, Guns N' Roses, and Metallica. For instance, the main character, Sol Badguy, was named after Queen's lead vocalist, Freddie Mercury. Both his real name, Frederick, and his last name were influenced by the singer, whose nickname was "Mr. Badguy".

Introduced in the first installment of the series (1998), Frederick Bulsara was one of the lead scientists of the Gear project, as well as being the prototypical Gear, dating from over a hundred years before the events of the Guilty Gear games. As a prototype, he is immune to the orders of Commander Gears. He was personally acquainted with Asuka R. Kreutz (typically known as That Man) prior to the Crusades. As Frederick, Sol created the "Outrage", which he called a supreme Anti-Gear weapon. The Outrage has eight components called "Jinki" (Godlike Weapons), which greatly amplify their wielders' magical ability. Later, he was himself recruited into the order, as a bounty hunter named Sol Badguy. Sol took part in the Crusades, during which he was a member of the Sacred Order of Holy Knights (Seikishidan), acquiring the nickname "Flame of Corruption" (背徳の炎, Haitoku no Honō). However, he later became disenchanted with the methods of the Sacred Order, and fled the order, taking with him the Fūenken (封炎剣; Fireseal). The theft earned him the enmity of Ky Kiske.

In 2175, Sol faced Justice directly. During the fight, which Justice won, she discovered that Sol was a Gear. Justice attempted to assert her power as a Commander Gear to control Sol, but was unable to do so. Exploiting her confusion and weakness from the fight, the Holy Order, led by Ky, sealed Justice away, bringing the war to an end. However, a Gear named Testament began a plan to free Justice, and to stop it, the Union of Nations held a tournament. The canon stated that Sol was the winner of the Tournament, which also resulted in Justice discovering that Sol was, in fact, Frederick. Justice, in her dying words, commented that she wished that "...the three of us..." could talk one last time, and Sol swore to kill Asuka.

In Guilty Gear X (2000), Sol has three endings, all of which involve a fight against Dizzy, who has a half-million dollar bounty on her head. However, he spares her life in all of them, losing against her in his second ending, and judging that she is not a threat to the world in the other two.

In the subsequent game, Guilty Gear X2 (2002), his story-line involved chasing down I-No. In his first ending, his defeat of I-No led to a direct confrontation with Asuka, who casually deflected all of Sol's attacks, saying that Sol was needed because soon a greater battle than the Crusades will occur. In Sol's second ending, Slayer informed him of the Post-War Administration Bureau's interest in Dizzy. In the third ending, he fought Dizzy, who had been possessed by Necro, after I-No knocked her off the Mayship, and sent Dizzy on her way to meet Johnny and May.

In Guilty Gear XX Accent Core Plus (2008), Sol had two endings. In one, I-No threw him back in time to fight his past self, Order-Sol. After both are weakened from the battle, I-No reappeared to murder Order-Sol, which, in turn, caused Sol's present form to cease existing. In his other ending, the same set of events played out, but Sol's present form, strangely, is unaffected by his past self's death. After escaping the time rift, Ky confronted and engaged him in battle. After the fight, Sol and Ky finally settled their differences and went their separate ways, with Ky asking Sol to promise that they will meet again. Though it was referenced in both Sol and Ky's endings, only Sol's told the events directly after the battle, which implied that Sol was the victor.