Gym Leader

Gym Leaders are trainers who run a Gym and battle trainers. If a trainer defeats a Gym Leader in battle, the trainer earns that Gym's badge. A trainer must earn eight badges before he or she may enter a Pokémon League.

Each region has eight official Gyms, although some cities, such as Saffron City, also have an unofficial gym which does not award a badge.

In the anime, the Pokémon League at the Orange Archipelago requires only four badges to enter.

Indigo League

Gym Leader	City	Badge	Use
Brock	Pewter City	Boulder Badge	Raises Attack stat in battle. Flash may be used out of battle.
Misty	Cerulean City	Cascade Badge	Traded Pokémon up to level 30 will obey. Cut may be used out of battle.
Lt. Surge	Vermilion City	Thunder Badge	Raises Speed stat in battle. Fly may be used out of battle.
Erika	Celadon City	Rainbow Badge	Traded Pokémon up to level 50 will obey. Strength may be used out of battle.
Koga/Janine	Fuchsia City	Soul Badge	Raises Defense stat in battle. Surf may be used out of battle.
Blaine	Cinnabar Island	Volcano Badge	Raises Special stat(s) in battle.
Sabrina	Saffron City	Marsh Badge	Traded Pokémon up to level 70 will obey.
Giovanni/Blue	Viridian City	Earth Badge	All traded Pokémon will obey.

Orange League

Gym Leader	Island	Badge
Cissy	Miken Island	Coral Eye Badge
Danny	Navel Island	Sea Ruby Badge
Rudy	Trovita Island	Spike Shell Badge
Luanna	Kumquat Island	Jade Star Badge

Johto League

Gym Leader	City	Badge	Use
Falkner	Violet City	Zephyr Badge	Raises Attack stat in battle. Flash may be used out of battle.
Bugsy	Azalea Town	Hive Badge	Traded Pokémon up to level 30 will obey. Cut may be used out of battle.
Whitney	Goldenrod City	Plain Badge	Raises Speed stat in battle. Strength may be used out of battle.
Morty	Ecruteak City	Fog Badge	Traded Pokémon up to level 50 will obey. Surf may be used out of battle.
Chuck	Cianwood City	Storm Badge	Traded Pokémon up to level 70 will obey. Fly may be used out of battle.
Jasmine	Olivine City	Mineral Badge	Raises Defense stat in battle.
Pryce	Mahogany Town	Glacier Badge	Raises Special stats in battle. Whirlpool may be used out of battle.
Clair	Blackthorn City	Rising Badge	All traded Pokémon will obey. Waterfall may be used out of battle.

Hoenn League

Gym Leader	City	Badge	Use
Roxanne	Rustboro City	Stone Badge	Raises Attack stat in battle. Cut may be used out of battle.
Brawly	Dewford Town	Knuckle Badge	Traded Pokémon up to level 30 will obey. Flash may be used out of battle.
Wattson	Mauville City	Dynamo Badge	Raises Speed stat in battle. Rock Smash may be used out of battle.
Flannery	Lavaridge Town	Heat Badge	Traded Pokémon up to level 50 will obey. Strength may be used out of battle.
Norman	Petalburg City	Balance Badge	Raises Defense stat in battle. Surf may be used out of battle.
Winona	Fortree City	Feather Badge	Traded Pokémon up to level 70 will obey. Fly may be used out of battle.
Tate & Liza	Mossdeep City	Mind Badge	Raises Special stats in battle. Dive may be used out of battle.
Wallace Adan	Sootopolis City	Rain Badge	All traded Pokémon will obey. Waterfall may be used out of battle.