A list of characters in the DC Animated Universe who first became prominent in Justice League and Justice League Unlimited.
- The Justice Leaguenote The Justice League: Superman, Batman, Wonder Woman, Green Lantern (John Stewart), The Flash, Hawkgirl, Martian Manhunter, Aquaman, Green Arrow, Black Canary, The Question, Metamorpho, Orion, Captain Atom, Vixen, Hawk & Dove, Big Barda, Vigilante, Shining Knight, S.T.R.I.P.E., Stargirl, Supergirl, Booster Gold, Mister Terrific, Steel, Doctor Fate, Zatanna, Fire, Ice, Red Tornado, Elongated Man, Crimson Avenger, B'wana Beast, Plastic Man, Power Girl, Black Condor, Bloodwynd, Triumph, Miss Martian, Green Lantern / Limelight (Jessica Cruz), Green Lantern (Hal Jordan), Green Lantern (Guy Gardner); Comic-Only: Blue Beetle, Steel II (Natasha Irons), All-Star, Zauriel, Doctor Occult, Blue Devil, Mary Marvel, Animal Man
- Allies & Friends of the Justice Leaguenote Green Lantern Corps: Katma Tui, Kilowog; Other Heroes: Captain Marvel, Hawkman, Deadman, Huntress; Legion of Super-Heroes; Others: King Faraday, Linda Park, Tracy Simmons, Mophir, the Justice Guild of America, General Wells
- Project Cadmusnote Project Cadmus, Amanda Waller, Wade Eiling, Tala, Emil Hamilton, Dr. Milo, Dr. Hugo Strange, Dr. Moon, Maxwell Lord, Rick Flagg Jr., Galatea, Doomsday, the Ultimen (Wind Dragon, Downpour, Shifter, Juice, Longshadow), Task Force X, General Hardcastle
- The Secret Societynote Gorilla Grodd, Sinestro, Giganta, Killer Frost, Atomic Skull, Bizarro, Cheetah, Shade, Star Sapphire, Parasite, Toyman, Metallo, Clayface
- Other Villainsnote Brainiac, Mongul, Despero, Draaga, the Thanagarian fleet, the Justice Lords, Ares, Hades, Circe, Aresia, Morgaine Le Fey, Mordred, Felix Faust, Shadow Thief, The Ophidians, Lord Orm, Ichthultu, A.M.A.Z.O., The Royal Flush Gangs, Ace, The Fatal Five (Emerald Empress, Tharok, The Persuader, Mano, Validus, Vandal Savage, Steven Mandragora, Solomon Grundy, Ultra-Humanite, Roulette, Doctor Destiny, Deadshot, Chronos, Ray Thompson, Tsukuri, Flash's rogues, The Trickster, Bloodsport II, Copperhead, Morgan Edge, G. Gordon Godfrey