Where to catch Diglett

In Paldea (Scarlet & Violet)

• Alfornada Cavern — Walk
• Asado Desert — Walk
• East Province (Area Three) — Walk
• Inlet Grotto — Walk
• South Province (Area Six) — Walk
• South Province (Area Two) — Walk, Static Encounter

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

• Coastal Biome — Walk
• Torchlit Labyrinth — Walk

In Johto & Kanto (Gold, Silver & Crystal)

• Diglett's Cave — Walk

In Kanto (Red, Blue & Yellow)

• Diglett's Cave — Walk

Diglett — full Pokédex entry