Where to catch Happiny

In Paldea (Scarlet & Violet)

• Pokémon League — Walk
• South Province (Area Five) — Walk
• South Province (Area One) — Walk
• South Province (Area Three) — Walk
• South Province (Area Two) — Walk
• West Province (Area One) — Walk

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

• Coastal Biome — Walk
• Savanna Biome — Walk
• Torchlit Labyrinth — Walk

Happiny — full Pokédex entry