Main Series Pokemon Games:
* Pokemon Gold, Silver, Crystal: Found in the Ilex Forest.
* Pokemon Ruby, Sapphire, Emerald: Found in the Petalburg Woods.
* Pokemon Diamond, Pearl, Platinum: Found in the Floccesy Ranch.
* Pokemon Black, White, Black 2, White 2: Found in the Floccesy Ranch.
* Pokemon X, Y: Found in the Azure Bay.
* Pokemon Sun, Moon, Ultra Sun, Ultra Moon: Found in the Poni Grove.
* Pokemon Sword, Shield: Found in the Dusty Bowl.
* Pokemon Brilliant Diamond, Shining Pearl: Found in the Floccesy Ranch.
* Pokemon Legends: Arceus: Found in the Obsidian Fieldlands.
* Pokemon Scarlet, Violet: Found in the West Province (Area Three).
Other Pokemon Games:
* Pokemon Ranger: Found in the game's world, though it's not always easy to catch.
* Pokemon Mystery Dungeon series: Available as a partner Pokemon in some games.
* Pokemon Rumble Rush: Can be caught in this mobile game.
* Pokemon Go: Can be hatched from eggs or encountered in the wild (though rare).
Note: Some of these games require specific conditions or methods to catch Pichu, such as breeding a Pikachu or evolving a Pichu.