Where do you get King's Rock in Pokemon FireRed?

Answer 1

you have to go to island 7 and go all the way down until you face a girl with chansey. Go to the right and a girl will have hitmontop. Go down and you see a poke ball get it and you get kings rock.

Answerfor once someone is right Answerat sevault canyon AnswerYou will alson need to have Pokemon knowing the moves Strength & Rock Smash as you will need them both to get to the King's Rock.

Also, im pretty sure slowbro holds it as an item, or that might be exclusive to heartgold/soul silver
The kings rock is in Sevault Canyon which is on island 7, to get to island 7 you need to obtain the rainbow pass.
it is on island 7 u need rock smash and strength after u beat a girl with chansey and a hitmontop then keep goin south and you'll c something dat looks lyk a pokeball use rock smash and strength and there u hav your king's rock