* Boulder Badge: Defeat Brock at Pewter City Gym (Rock-type).
* Cascade Badge: Defeat Misty at Cerulean City Gym (Water-type).
* Thunder Badge: Defeat Lt. Surge at Vermilion City Gym (Electric-type).
* Rainbow Badge: Defeat Koga at Fuchsia City Gym (Poison-type).
* Soul Badge: Defeat Sabrina at Saffron City Gym (Psychic-type).
* Marsh Badge: Defeat Blaine at Cinnabar Island Gym (Fire-type).
* Volcano Badge: Defeat Giovanni at Viridian City Gym (Ground-type).
* Earth Badge: Defeat the Elite Four at Indigo Plateau (various types).
Remember, the badge order is determined by the gym you choose to battle first. This list follows the typical order players encounter gyms in Pokemon Yellow.