Where to catch Ralts

In Paldea (Scarlet & Violet)

• Los Platos — Walk
• South Province (Area One) — Walk

In Kitakami (Scarlet & Violet – The Teal Mask)

• Kitakami Hall — Walk
• Kitakami Wilds — Walk
• Mossfell Confluence — Walk
• Oni Mountain — Walk
• Paradise Barrens — Walk
• Reveler's Road — Walk
• Timeless Woods — Walk
• Wistful Fields — Walk

In Hoenn (Ruby, Sapphire & Emerald)

• Route 102 — Walk

Ralts — full Pokédex entry