Rapidash locations — where to catch

In Hisui (Legends: Arceus)

• Horseshoe Plains — Walk

In Johto & Kanto (HeartGold & SoulSilver)

• Mt. Silver — Walk
• Route 28 — Walk

In Sevii Islands (FireRed & LeafGreen)

• Kindle Road — Walk
• Mt. Ember — Walk

In Johto & Kanto (Gold, Silver & Crystal)

• Mt. Silver — Walk
• Pewter City — NPC Trade
• Route 28 — Walk

Other games (4)

• Sword / Shield (Gen 8): Kanto, Bridge Field, Hammerlocke Hills, Lake of Outrage, Rolling Fields
• Let's Go, Pikachu! / Let's Go, Eevee! (Gen 7): Kanto Route 17
• Black / White (Gen 5): Unova Route 12
• XD (Gen 3): Citadark Isle

Rapidash — full Pokédex entry