Where to catch Cleffa

In Kitakami (Scarlet & Violet – The Teal Mask)

• Crystal Pool — Walk
• Infernal Pass — Walk
• Kitakami Hall — Walk
• Oni Mountain — Walk
• Reveler's Road — Walk

In Johto & Kanto (Gold, Silver & Crystal)

• Route 34 — Gift, Walk

Cleffa — full Pokédex entry