Professor Oak’s first name in the Pokémon series is Samuel. He is the Pokémon professor associated with the Kanto region and serves as a mentor and research authority in the original games and anime.
In Pokémon Red, Green, Blue, and Yellow, Oak introduces the player to Pokémon research and gives the player a first partner Pokémon. His grandson, known internationally as Gary Oak in the anime and as the rival character in the games, begins the adventure alongside the player.
Professor Oak studies Pokémon and their relationships with humans. His role helped establish the recurring Pokémon-professor tradition, in which a scientist provides the player with a Pokédex and a starter Pokémon.
The name “Professor Oak” is used far more often than Samuel, which is why many fans know the title but not the given name. Later regions introduced their own professors, including Elm, Birch, Rowan, Juniper, and Kukui.