go to the ligthouse then talk to the blonde guy he is the gym leader then go to the ggym
The only way to get a gym badge is to challenge the corresponding gym leader and win.
you beat the gym leader
you have to use the HM surf and surf behind the gym and go in the cave. go to the other side of the dragon temple and go in. awnser the old man's questions and the gym leader will come in and give you the badge. This is to get the 8th Johto gym badge. To get the Kanto one search: how do you get to the 8th Kanto gym badge
Beat the 8th Gym leader.
You will need to defeat Volkner, the Sunyshore City Gym Leader.
You must go to the Pokemon Gym. Beat the gym leader and he awards you with the 8th gym badge
In Pokémon Sapphire, the Gym Badges in order would be Stone Badge being the first one that you get after beating Roxanne, the leader of the Rustboro City Gym. The 2nd Gym Badge will be the Knuckle Badge which you will get after beating Brawly, the Gym Leader of Dewford Town. The third Badge will be the Dynamo Badge which will be given to you if you beat Wattson, the Mauville City Gym Leader. The 4th Badge is the Heat Badge and you will get that once you beat Flannery, the Gym Leader of Lavaridge Town. the 5th Badge you will get will be from your in-game Dad, Norman, the Gym Leader of Petalburg City, Normal will award you the Balance Badge after you beat him. The 6th Badge will come from Winona, the Fortree City Gym Leader, she will give you the Feather Badge. The 7th Badge will come from the Mossdeep City Gym Leaders, Tate and Liza. The 8th Gym Badge is the Rain Badge.
You can only get the Sixth Badge from the Sixth gym leader. After defeating the Sixth gym leader, the gym leader will give you the Sixth Badge.
1st badge: The Boulder Badge, given to you by Brock, the Rock-type gym leader of Pewter City. 2nd badge: The Cascade Badge, given to you by Misty, the Water-type gym leader of Cerulean City. 3rd badge: The Thunder Badge, given to you by Lt. Surge, the Electric-type gym leader of Vermillion City. 4th badge: The Rainbow Badge, given to you by Erika, the Grass-type gym leader of Celadon City. 5th badge: The Soul Badge, given to you by Koga, the Poison-type gym leader of Fushia City. 6th badge: The Marsh Badge, given to you by Sabrina the Psychic-type gym leader of Saffron City. 7th badge: The Volcano Badge, given to you by Blaine, the Fire-type gym leader of Cinnabar Island. 8th badge: The Earth Badge, given to you by Giovanni, the Ground-type gym leader and leader of Team Rocket from Viridian City.
go to the final badge.. defeat the 8th gym leader to qualify for Pokemon league..
you dive to get to sootopolis which is in the south east from mosdeep then fight groudon then you can challenge the gym leader and get your 8th gym badge. then u challenge the elite 4.
I get my 8th badge in Sootopolis gym.