- In the Pokémon Red and Blue beta, Diglett was originally to use its Japanese name, "Digda", as its English name. This name was retained in the German localization of the games.
- Diglett has the second lowest base HP of any Pokémon, after Shedinja.
- It also has the lowest base Defense of any Ground-type Pokémon.
- In Pokémon Mystery Dungeon: Red Rescue Team and Blue Rescue Team, after the first Mt. Steel mission, Diglett mentions having feet. It is mentioned again as being one of the seven mysteries of Pokémon in a letter, alongside Arbok's pattern changes and the inside of Forretress's shell.
- Diglett and its evolved form share their category with Drilbur. They are all known as the Mole Pokémon.
- Diglett, despite being one of the smallest and [[lightest Pokémon, has the ability to breed with Wailord, the Pokémon with the greatest height. This is similar to HSOWA.
- In the Pokéathlon Hurdle Dash, Diglett and Dugtrio are seen to go underground rather than physically jump out of the ground.
- Since Generation V, when Diglett and Dugtrio are sent out, they merely fade onto the screen instead of dropping down like all other Pokémon.
- In the Poké Transfer, Diglett and Dugtrio run between bushes rather than jump.
- Diglett is immune to the move Telekinesis. However, the effect of the move remains if Diglett obtains it via Baton Pass.
- In Pokémon HeartGold and SoulSilver, if Diglett is the player's partner Pokémon, and the player goes to the Pokémon Center, Diglett jumps to its Poké Ball to be healed.
- In the English dub of the anime, Gary stated that Diglett is able to pull its head underground at the speed of light.
- Diglett is listed in Pokémon Stadium as having Acid as a valid move, despite not being able to learn the move.
