Jynx locations — where to catch

In Sinnoh (Diamond, Pearl & Platinum)

• Snowpoint Temple — Walk

In Johto & Kanto (HeartGold & SoulSilver)

• Ice Path — Walk
• Seafoam Islands — Walk

In Kanto (FireRed & LeafGreen)

• Cerulean City — Trade

In Johto & Kanto (Gold, Silver & Crystal)

• Ice Path — Walk

In Kanto (Red, Blue & Yellow)

• Cerulean City — NPC Trade

Other games (5)

• Sword / Shield — The Isle of Armor (Gen 8): Frigid Sea, Frostpoint Field, Giant's Bed, Max Lair, Slippery Slope, Snowslide Slope
• Let's Go, Pikachu! / Let's Go, Eevee! (Gen 7): Seafoam Islands
• Ultra Sun / Ultra Moon (Gen 7): Poke Pelago, Seaward Cave
• X / Y (Gen 6): Frost Cavern
• Black / White (Gen 5): Giant Chasm

Jynx — full Pokédex entry