Holy Knights Of The Sacred Order-
Sol Badguy/Frederick. Guilty Gear, Guilty Gear X, Guilty Gear X: Advance Edition, Guilty Gear Petit, Guilty Gear XX, Guilty Gear Isuka.
Ky Kiske. Guilty Gear, Guilty Gear X ,Guilty Gear X: Advance Edition, Guilty Gear XX, Guilty Gear Isuka.
Kliff Undersn.Guilty Gear, Guilty Gear XX.

Assassins Syndicate-
Slayer.Guilty Gear XX, Guilty Gear Isuka.
Zato-One.Guilty Gear, Guilty Gear X,  Guilty Gear X: Advance Edition, Guilty Gear Petit, Guilty Gear XX, Guilty Gear Isuka.
Millia Rage.Guilty Gear, Guilty Gear X, Guilty Gear X: Advance Edition, Guilty Gear Petit, Guilty Gear XX, Guilty Gear Isuka.
Venom. Guilty Gear X, Guilty Gear X: Advance Edition, Guilty Gear Petit, Guilty Gear XX, Guilty Gear Isuka.

Jellyfish Pirates-
Johnny. Guilty Gear (cameo appearance), Guilty Gear X, Guilty Gear X: Advance Edition, Guilty Gear Petit, Guilty Gear XX, Guilty Gear Isuka.
May.Guilty Gear, Guilty Gear X, Guilty Gear X: Advance Edition, Guilty Gear Petit, Guilty Gear XX, Guilty Gear Isuka.

Japanese-
Anji-Mito. Guilty Gear X, Guilty Gear X: Advance Edition, Guilty Gear Petit, Guilty Gear XX, Guilty Gear Isuka.
Baiken. Guilty Gear (unlockable character), Guilty Gear X, Guilty Gear Petit, Guilty Gear X: Advance Edition, Guilty Gear XX, Guilty Gear Isuka.
Chipp Zanuff. Guilty Gear, Guilty Gear X, Guilty Gear X: Advance Edition, Guilty Gear Petit, Guilty Gear XX, Guilty Gear Isuka.

Gears-
Testament.Guilty Gear (secondary boss), Guilty Gear X (secondary boss), Guilty Gear Petit, Guilty Gear X: Advance Edition, Guilty Gear XX, Guilty Gear Isuka.
Justice.Guilty Gear (boss), Guilty Gear XX (unlockable character), Guilty Gear Isuka.
Dizzy. Guilty Gear X (boss), Guilty Gear X: Advance Edition, Guilty Gear Petit, Guilty Gear XX, Guilty Gear Isuka.

Shusen Kanrikyoku (Postwar Administration Bureau)-
Robo-Ky.Guilty Gear X (Ky Kiske on Guilty Gear Mode), Guilty Gear X: Advance Edition, Guilty Gear Petit, Guilty Gear XX (as official character).(Unlockable character).
 

Assistants of 'That Man'-
I-No.Guilty Gear XX, Guilty Gear Isuka.
Raven. Guilty Gear XX (story mode appearances).

Outsiders-
Bridget. Guilty Gear XX, Guilty Gear Isuka.
Jam Kuradoberi. Guilty Gear X, Guilty Gear X: Advance Edition, Guilty Gear Petit, Guilty Gear XX, Guilty Gear Isuka.
Potemkin.Guilty Gear, Guilty Gear X,  Guilty Gear X: Advance Edition, Guilty Gear Petit, Guilty Gear XX, Guilty Gear Isuka.
Axl.Guilty Gear, Guilty Gear X, Guilty Gear X: Advance Edition, Guilty Gear Petit, Guilty Gear XX, Guilty Gear Isuka.
Faust/Dr Baldhead.Guilty Gear, Guilty Gear X, Guilty Gear X: Advance Edition, Guilty Gear Petit, Guilty Gear XX, Guilty Gear Isuka.
Zappa.Guilty Gear XX, Guilty Gear Isuka.
Fanny.Guilty Gear Petit.

Plot Characters-
'That Man'. Guilty Gear XX (story mode appearance).
President Gabriel. Guilty Gear X, Guilty Gear X: Advance Edition, Guilty Gear Petit, Guilty Gear XX, Guilty Gear Isuka.
April. Guilty Gear X, Guilty Gear X: Advance Edition, Guilty Gear Petit, Guilty Gear XX.
Eddie. Guilty Gear, Guilty Gear X, Guilty Gear X: Advance Edition,Guilty Gear Petit, Guilty Gear XX, Guilty Gear Isuka.
S-Ko. Guilty Gear XX, Guilty Gear Isuka.
Erica Bartholomew. Background character, no game appearance.

Necro & Undine. Guilty Gear X, Guilty Gear X: Advance Edition, Guilty Gear Petit, Guilty Gear XX, Guilty Gear Isuka.
 

Isuka Characters-
Leopoldon. Guilty Gear Isuka.
A.B.A.Guilty Gear Isuka.
Robo-Ky MK II. Guilty Gear Isuka (customisable character.)