Professor Oak appears in Pokémon Origins as a Pallet Town-based Pokémon professor and researcher. He mentors protagonists Red and Blue, entrusting them with starter Pokémon and the mission to complete the comprehensive Pokédex encyclopedia. Completing the Pokédex represents his lifelong goal, viewed as vital for Pokémon research.

Oak demonstrates a strong commitment to Pokémon's ethical treatment, confronting any mistreatment or derogatory comments. This principle drives his direct challenge to Giovanni, the Viridian Gym Leader and Team Rocket boss, over exploiting Pokémon for crime. During the Viridian Gym confrontation, Oak supports Red's refusal to accept the Earth Badge from the implicated Giovanni.

As a mentor, Oak provides Red guidance beyond initial training, observing Red's "klutz" tendency. He helps Red transform this trait into an analytical strength during battles and research. Oak also facilitates Red's journey by supplying essential tools like Poké Balls and the Pokédex.

Oak extends his support to his grandson Blue, providing him a starter Pokémon too. While encouraging competition between Red and Blue, Oak remains focused on their growth as trainers and researchers. He later witnesses their climactic battle at the Pokémon League, where Red defeats Blue to become Champion.

A notable aspect of his portrayal is his vocal dissonance; his voice features a notably younger sound than his appearance suggests, distinguishing him from other iterations.