Shellder locations — where to catch

In Paldea (Scarlet & Violet)

• Asado Desert — Walk
• East Paldean Sea — Walk
• East Province (Area One) — Walk
• East Province (Area Two) — Walk
• Glaseado Mountain — Walk
• North Paldean Sea — Walk
• North Province (Area One) — Walk
• North Province (Area Three) — Walk
• Poco Path — Walk
• South Paldean Sea — Walk
• South Province (Area Five) — Walk
• South Province (Area Four) — Walk
• South Province (Area One) — Walk
• South Province (Area Six) — Walk
• West Paldean Sea — Walk
• West Province (Area One) — Walk
• West Province (Area Two) — Walk

In Sinnoh (Diamond, Pearl & Platinum)

• Floaroma Town — Super Rod
• Fuego Ironworks — Super Rod
• Route 205 — Super Rod
• Valley Windworks — Super Rod

In Johto & Kanto (HeartGold & SoulSilver)

• Cinnabar Island — Good Rod, Super Rod
• New Bark Town — Good Rod, Super Rod
• Pallet Town — Good Rod, Super Rod
• Route 26 — Good Rod, Super Rod
• Route 27 — Good Rod, Super Rod
• Route 47 — Good Rod, Super Rod
• Sea Route 20 — Good Rod, Super Rod
• Sea Route 21 — Good Rod, Super Rod
• Sea Route 41 — Good Rod, Super Rod
• Vermilion City — Good Rod, Super Rod

In Kanto (FireRed & LeafGreen)

• Cinnabar Island — Super Rod
• Pallet Town — Super Rod
• S.S. Anne — Super Rod
• Vermilion City — Super Rod

In Sevii Islands (FireRed & LeafGreen)

• Five Island — Super Rod
• Icefall Cave — Super Rod
• One Island — Super Rod

In Johto & Kanto (Gold, Silver & Crystal)

• Cinnabar Island — Good Rod, Super Rod
• New Bark Town — Good Rod, Super Rod
• Olivine City — Super Rod
• Pallet Town — Good Rod, Super Rod
• Route 26 — Good Rod, Super Rod
• Route 27 — Good Rod, Super Rod
• Sea Route 20 — Good Rod, Super Rod
• Sea Route 21 — Good Rod, Super Rod
• Sea Route 41 — Good Rod, Super Rod
• Vermilion City — Good Rod, Super Rod

In Kanto (Red, Blue & Yellow)

• Cinnabar Island — Super Rod
• Route 11 — Super Rod
• Route 17 — Super Rod
• Route 18 — Super Rod
• Route 6 — Super Rod
• Sea Route 19 — Super Rod
• Sea Route 20 — Super Rod
• Sea Route 21 — Super Rod
• Seafoam Islands — Super Rod, Walk
• Vermilion City — Super Rod

Other games (10)

• Brilliant Diamond / Shining Pearl (Gen 8): Floaroma Town, Fuego Ironworks, Route 205, Valley Windworks
• Sword / Shield — The Isle of Armor (Gen 8): Challenge Beach, Courageous Cavern, Fields of Honor, Loop Lagoon, Workout Sea
• Sword / Shield (Gen 8): Dusty Bowl, East Lake Axewell, Giant's Seat, North Lake Miloch, South Lake Miloch, West Lake Axewell
• Let's Go, Pikachu! / Let's Go, Eevee! (Gen 7): Seafoam Islands
• Ultra Sun / Ultra Moon (Gen 7): Kala’e Bay, Kalae Bay
• Sun / Moon (Gen 7): Kala’e Bay, Kalae Bay, Poke Pelago
• X / Y (Gen 6): Kalos Route 8
• Black 2 / White 2 (Gen 5): Humilau City, Seaside Cave, Undella Town, Route 13, Unova Route 13
• Black / White (Gen 5): Undella Bay, Undella Town, Route 13, Unova Route 13
• XD (Gen 3): Cipher Key Lair

Shellder — full Pokédex entry