The Pokémon Company has unveiled a new batch of screenshots and details for Alolan Pokémon in Pokémon Let’s Go Pikachu and Let’s Go Eevee:
Alolan Form Pokémon
Certain Pokémon have regional variants—that is, they have adapted to the unique environment of one specific region and look and behave differently from the same species found in other regions. The regional variants of the Alola region are known as Alolan forms.
If you’ve caught Pokémon in their Alolan form in Pokémon GO, you’ll be able to bring them over to Pokémon: Let’s Go, Pikachu! or Pokémon: Let’s Go, Eevee! in that same form. But if you haven’t caught any, don’t worry—there are visitors from the Alola region in Pokémon: Let’s Go, Pikachu! and Pokémon: Let’s Go, Eevee! who will be happy to trade their Alolan form Pokémon with you.
Pokémon Blog 
One thought on “Pokémon Let’s Go Alolan Pokémon can be transferred from Pokémon GO and traded in-game with Trainers from Alola”