In Pokémon Brilliant Diamond and Shining Pearl, an abundance of Pokémon will be unlocked post-game when you acquire the National Pokédex, including Pikachu. Pikachu has been a fan-favourite since the dawn of Pokémon, so it makes sense that you may want one for your collection!
In this guide, we explain how to unlock and where to find Pikachu (and Pichu).
How To Unlock Pikachu
First things first, you will need to have beaten the Elite Four and Cynthia, thus crowning yourself the League Champion in Pokémon Brilliant Diamond and Shining Pearl. Then, if you haven't already, you will need to complete your Sinnoh Pokédex by encountering every Pokémon in the region, including the illusive Drifloon.
After this, you can speak with both Professor Rowan and Professor Oak at the Pokémon Research building in Sandgem Town to have your Sinnoh Pokédex upgraded to the National Pokédex. Pikachu (and Pichu) will now be available to catch!
Where To Find Pikachu
In Pokémon Brilliant Diamond and Shining Pearl, Pikachu is known to only be found in one place. That is the Trophy Garden at the very back of the Pokémon Mansion; here, Pichu and Pikachu have a chance of spawning, alongside Eevee and other special, daily Pokémon. You can find out the daily Pokémon by speaking with Mr Backlot in the room in the Mansion's eastern wing.
The Trophy Garden is along Route 212, south of Hearthome City, and can be accessed by entering the Pokémon Mansion and going through the northern door straight ahead from the entrance. There's plenty of exploring to be done and wild Pokémon to be caught here!
Good luck catching yourself a Pikachu, and don't forget to get your hands on a Ditto too if you're thinking about breeding them. Pikachu is also one of the few Pokémon who can be walked around Amity Square, too, so check that out when you need some downtime away from battling and catching 'em all.