You need to have defeated the other seven first. Once you have, you'll be able to get in. It's a Ground-Type-based gym, and the leader is Giovanni.
Giovanni
Dugtrio, Rhydon, Nidoking, Nidoqueen, Rhyhorn.
You have to beat all of the other gyms otherwise it's impossible.
The 8th gym in Pokemon Yellow is situated in Viridian City. It is the second city you encounter when you first begin your game.
Wallace is the 8th gym leader PEOPLE!!!!!!!!!!!
In Pokémon Yellow, the 8th Gym Leader, the Viridian City Gym Leader, Giovanni's Pokémon are Persian, Dugtrio, Nidoqueen, Rhydon and Nidoking. Persian is at Level 53, Dugtrio at Level 50, Nidoqueen at Level 53, Nidoking at Level 55 and Rhydon at Level 55.
In the 8th gym. he is the gym leader
1. SP (spell check for all you n00bletts out there) 2. The 8th gym leader is in Viridian City. Its the city after your hometown.
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 8th gym leader is Drayden, who uses Dragon-type Pokemon. You face him in Opelucid City.
you beat the gym leader
beat the 8th gym