• English / United States: Professor Samuel Oak
• Japanese / Japan: オーキド ユキナリ博士
• Japanese (Romanized) / Japan: Yukinari Okido-hakase
• Japanese (TL) / Japan: Professor Yukinari Okido
• French / France: Professeur Sammy Chen

Professor Oak is the leading Pokémon Professor of the Kanto Region. In addition to his research duties, it is his responsibility to distribute the beginner's Pokémon - Bulbasaur, Squirtle, and Charmander - to trainers just starting out on their Pokémon journey. In addition, he is responsible for giving trainers basic gear that will help them on their journey, such as a PokéDex and PokéBalls. The morning of the start of Ash Ketchum's Pokémon Journey, Ash Ketchum woke up late and by the time he had reached Oak's office, the Professor had already given away the beginner Pokémon. Thus, Professor Oak was forced to give Ash Ketchum a Ash's Pikachu instead. Captured Pokémon can also be transferred to him, and he takes care of Ash Ketchum's unused Pokemon. He gives helpful advice to Ash Ketchum and the group throughout their journey.

Professor Ivy read an article by Professor Oak titled: "The Challenges facing Anthro-Pokémon Global Cohabitation" and told him that she found it absolutely fascinating.

Pokémon Live Caster Senryū Sayings

At the end of each Pokémon Live Caster in the Japanese Pocket Monsters Best Wishes episodes, Professor Samuel Oak would introduce his senryū with a saying. They were often reused at random intervals. Below is a list of the sayings.

Translation	Japanese
Finally, let's end this with a Pokémon senryu.	saigo wa, Pokemon senryu de shimeru to shiyou
Well, finally, a Pokémon senryu.	de wa, saigo wa pokemon senryu ja
Well then, let's end this with a Pokémon senryu.	sore de wa, Pokemon senryu de shimeru to shiyou
Finally, we'll end this with a Pokémon senryu.	Saigo wa, Pokemon senryu de shimeru zo
Well, let's end this with a Pokémon senryu.	de wa, pokemon senryu de shimeru to shiyou
Well, finally, let's do a Pokémon senryu	de wa saigo wa, pokemon senryu de ikusou
Okay, finally, let's do a Pokémon senryu	Saa, saigo wa, Pokemon senryu de ikusou