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.
In the mahogany gym
The seventh gym leader is Candice, the Ice Type leader. She is at Snowpoint City.
You go on to defeat the eight gym leader.
pryce the ice type gym leader
The 7th leader is Blaine. He uses fire pokemon.
Candice
On cinnibar island.
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 eighth gym leader still awaits, as well as the whole of Kanto.
the best way to beat the 7th gym leader is with a fire type Pokemon
Cinnibar island.
Brock is the first gym leader in pewter city.