I'm pretty sure he's on Cinnabar Island. You need to get HM Surf from the Safari Zone, then sail south from Pallet Town. Eventually you'll get to the island. Then you'll need to complete a "dungeon" to get the key to the gym. The leader is fire-themed.
The 7th gym leader in Pokemon yellow is in Cinnebar Island, which is south of Pallet Town. You need a Pokemon with Surf to get there.
snowpoint city
Candice
Cinnabar Island
The sixth gym is in Fuschia City, where you fight Koga, Poison type leader.
The 7th gym leader in Pokemon yellow is in Cinnebar Island, which is south of Pallet Town. You need a Pokemon with Surf to get there.
The 7th gym leader is Blaine. He the gym leader of Cinnabar Island gym. He uses Fire type Pokemon and he will give you the TM that contains Fire Blast when you defeat him.
Brock is the first gym leader in pewter city.
Giovanni
i cant explain
celadon city
The 7th leader is Blaine. He uses fire pokemon.
In the town where Ltg. Serge is a gym leader there is an officer there with a squirtle. Beat the gym leader and talk to her afterwards.
The gym leader of Mahogany Town. He uses Ice-type Pokemon. You face him as the 7th gym leader in the game.
His Pokemon are: Vanillish,Cryogonal,And Beartic.
The 5th gym in Pokemon Yellow is the Fuchsia City gym. The gym leader is Koga who specializes in Poison/Bug type Pokemon. Once won you will recieve the Soul badge, TM06 - Toxic, & be able to use HM03 Surf out of battle.
snowpoint city