Where to catch Rhydon

In Blueberry Academy (Scarlet & Violet – The Indigo Disk)

• Canyon Biome — Static Encounter
• Savanna Biome — Walk

In Johto & Kanto (Gold, Silver & Crystal)

• Blackthorn City — NPC Trade, Trade

In Kanto (Red, Blue & Yellow)

• Cerulean Cave — Walk
• Cinnabar Island — Walk

Rhydon — full Pokédex entry