Where to catch Weepinbell

In Kitakami (Scarlet & Violet – The Teal Mask)

• Mossfell Confluence — Walk

In Johto & Kanto (Gold, Silver & Crystal)

• Route 24 — Walk
• Route 25 — Walk
• Route 44 — Walk

In Kanto (Red, Blue & Yellow)

• Cerulean Cave — Walk
• Route 12 — Walk
• Route 13 — Walk
• Route 14 — Walk
• Route 15 — Walk

Weepinbell — full Pokédex entry