Professor Samuel Oak, known as in Japan, is a fictional character in the Pokémon franchise that debuted in 1996 video game Pokémon Red and Green. In these games, he is responsible both for teaching the player about how the world of Pokémon works, as well as giving the player-character their first Pokémon. He has since gone on to appear in subsequent entries in the series as well as spin-off games such as Pokémon Snap and Pokémon Channel. He also has a prominent recurring role in Pokémon: The Series, acting as a guide and starting off the journey for series protagonist Ash Ketchum by giving him a Pikachu.
Since his debut, Professor Oak has received positive reception due to his friendly appearance, with critics declaring him to one of the best characters in the franchise and a series staple. Additionally commentary was made regarding an unused battle the player could have had with him, with critics disappointed upon the discovery the battle was cut.
Concept and creation
Developed by Game Freak and published by Nintendo, the Pokémon series began in Japan in 1996 with the release of Pokémon Red and Blue for the Game Boy. In these games, the player assumes the role of a Pokémon Trainer whose goal is to capture and train creatures called Pokémon. Players use the creatures' special abilities to combat other Pokémon, and some can transform into stronger species, or evolve. The ultimate goal is to complete the Pokédex, a comprehensive Pokémon encyclopedia, by capturing, evolving, and trading to obtain creatures from all Pokémon species.
Professor Samuel Oak is designed as an old man with short hair and wearing formal laboratory attire such as a lab coat. Although depicted as being both smart and friendly, he is also typically depicted as being rather forgetful, most notably forgetting the name of his grandson. His English name is derived from the deciduous oak tree, with Game Freak stating that the name was chosen due to it being "dependable due to its longevity" as well as sounding similar to his Japanese name, Ohkido, which also may originate from orchid. Oak's name would set a trend where future Pokémon professors in the series would be named after other tree species or flora such as rowan, and sycamore. According to Game Freak developer Akihito Tomisawa, when needing a full name for the character on the Pokédex, he arbitrarily decided to name him after Japanese anthropologist , which was later officially adopted as the character's name.
In-universe he has a grandson known as Blue, also known as Gary in the anime, is the rival of the protagonist in Red and Blue. He also has a granddaughter known as Daisy. Earlier in his life he also had a close relationship with the Elite Four member Agatha, however, she revealed it fell a part when he left competitive battling and describing him now as a "shadow of his former self."
In Pokémon Sun and Moon, Samson Oak is introduced as the cousin of Samuel who resides in the Alola region. Although they both share similarities in both design and profession, Samson is more relaxed and depicting as having tanned skin, longer hair and wears a Hawaiian shirt, shorts and flip-flops. Similarly, Pokémon Home introduces a variant of Professor Oak called "Grand Oak". Whilst looking similar to the former, as well as both being inventors, he instead sports longer, white hair, a beard, and green, arrow-shaped sunglasses. as well as giving the player a choice between the Grass-type Pokémon Bulbasaur, Water-type Pokémon Squirtle, and Fire-type Pokémon Charmander, with Grass beating Water, Water beating Fire, and Fire beating Grass. He also gives them a device he created called a Pokédex, which allows them to catalog Pokémon they either see or catch, with the goal that they would catalog all Pokémon in the region. After their rival becomes champion of the Pokémon League and is defeated by the player, Oak will ush over to the Indigo League following hear that Blue defeated the Elite Four and will induct the player into the Pokémon Hall of Fame. An unused battle with Professor Oak can be found in the games' code featuring a team of five Pokémon, including the fully evolved starter that stayed behind with Oak. In Pokémon Yellow, Professor Oak gives the player a Pikachu instead of one of the three original Starter Pokémon. This is based on the Pokémon TV series, where protagonist Ash Ketchum receives a Pikachu because he slept in and missed the others. The rival, meanwhile, receives an Eevee. although will also gift the player the National Pokédex. Another pair of remakes, Pokémon Let's Go, Pikachu! and Let's Go, Eevee!, were released, again with Oak in a similar capacity. Similar to Yellow, the player does not get one of the original trio; instead, depending on the version chosen, they will receive either a Pikachu or Eevee from Oak. In a trailer for the games, Oak appears alongside Pokémon Gos Professor Willow to discuss an unidentified Pokémon, with Oak eventually revealing it to be the Mythical Pokémon Meltan.
In Pokémon Gold and Silver, Oak once again teaches about the world of Pokémon, as well as give the player a Pokédex, and is met later by the player during a meeting with a man named Mr. Pokémon. Later, the player receives a radio, which they can use to listen to a show Oak does with DJ Mary. He returns in similar capacity in the games' remakes, [[Pokémon HeartGold and SoulSilver|HeartGold and
SoulSilver]]. In these games, Oak gives the player the National Pokédex as well as access to the Pal Park; the latter was changed in the remakes into him giving access to the Ramanas Park instead. Additionally, he is responsible for the Oak's Letter event, whereby giving him the letter with the Mythical Pokémon Shaymin. Other games also feature relatives of Oak. His cousin, Professor Samson Oak, appears in Pokémon Sun and Moon. In these games, Samson is studying the regional forms of Pokémon in the Alola region. He later returns in the enhanced versions, Ultra Sun and Ultra Moon, where he also is in-charge of the Totem Sticker collectables by exchanging the player's stickers in return for them to fight Totem Pokémon. Another variant of Professor Oak, referred to as Grand Oak, appears in the app Pokémon Home. In the app, he serves as the creator of the online system that allows for trading Pokémon, with the desire of creating the ultimate Pokédex with all Pokémon transferred to the app.
Professor Oak has also appeared in multiple spin-off titles, such as in Pokémon Stadium and its sequel where he operates Pokémon transferring via the Transfer Pak. He is able to be battled in Pokémon Masters EX, in which he is partnered with both a Mew and a Nidorino. In the English version of the game, Oak is voiced by Joe J. Thomas, Appearing in Pokémon Play It! and its sequel, Oak rewards the player with a certificate for answering questions correctly. and the titular Pokémon Channel. In other games, such as Pokémon Puzzle Challenge, Pokémon Puzzle League, and PokéROM, he serves as a guide or narrator for the game; the latter game is voice by his at the time anime voice actor, Stan Hunt.
In the Pokémon Trading Card Game, a Professor Oak card first appeared in the original Base Set. He has since appeared on trading cards across multiple sets, with one even being designed by Japanese animator and director . One of these cards, called Professor's Research, appears in the mobile game Pokémon Trading Card Game Pocket. In October 2025, an event took place in the game where players could earn Professor Oak-themed cosmetics. Alongside his appearance in Base Set, a card known as "Imposter Professor Oak" also debuted in the same set. The card featured a more villainous-looking design, and has the exact opposite effect of Oak's card when played. The Imposter Professor Oak has gone to appear in a few other sets and was meant to appear in Gold and Silver, but was scrapped during the games' development.
Other media
In Pokémon: The Series, Professor Oak first appeared in the debut episode, "Pokémon, I Choose You!", where he provides the series protagonist Ash Ketchum his first Pokémon, a Pikachu, at his lab in Pallet Town after Ash missed out on the original three Starters due to oversleeping. This sequence of events are also retold in Pokémon the Movie: I Choose You!. The episode also introduces his grandson and Ash's rival, Gary, who was the recipient of one of the Starters from his grandfather. In the following season, Oak would send Ash and his friends to the Orange Islands to retrieve the GS Ball from fellow Professor Ivy. This was followed up in the following season where Oak is unable to figure out the GS Ball and asks Ash to take the ball to an expert named Kurt in the Johto region. This storyline was later dropped after Kurt received the ball. Professor Oak would appear across multiple episodes across the later seasons; between his original appearance and 2006, Oak had appeared in more than 400 episodes. He appears at the beginning of Pokémon the Series: Black & White where he travels with Ash to the Unova region. He would continue to make appearances in Pokémon the Series: Sun & Moon, alongside Samson Oak, as well as in Pokémon Journeys, eventually appearing the final episode of the original series "The Rainbow and the Pokémon Master".
Within the show, Oak is the neighbours with both Ash and his mother, Delia Ketchum. He is often seen together with Delia in many of their appearances. Across the show, he would house many of the Pokémon at his lab that Ash has caught across his travels over different regions. In some of his appearances, he is known to own both a Dragonite and a Rotom.
Professor Oak has also made a number of appearances in the Pokémon movies typically alongside Delia, as seen in Pokémon: The Movie 2000 and Pokémon 3: The Movie. He made a prominent appearance in the movie Pokémon 4Ever, where he appeared in the movie as a child Pokémon Trainer from the past named Sammy. In the movie, Sammy is travelling through a magic forest and comes across the Pokémon Celebi. He saves Celebi from a hunter, with Celebi in turn travelling in-time with Sammy where they meet Ash, Misty and Brock. After Celebi is captured to destroy the forest by the antagonist Iron Mask Marauder, a member of Team Rocket, Ash, Sammy, and the Pokémon Suicune work together to save Celebi and the forest. with his encounter with Celebi inspired him to become a scientist and Pokémon expert. where he is voiced by Kyle Hebert in English and Katsuji Mori in Japanese. he has also featured in both The Electric Tale of Pikachu and Pokémon Pocket Monsters.
Critical reception
In a 2021 poll ranking the popularity of the series' Pokémon professors, readers of the Japanese website NetLab ranked Professor Oak to be the most popular across the first eight generations, with Oak taking nearly 30% of all votes; readers cited his appearance in the anime for why they voted for him. Crunchyroll News writer Daniel Dockery felt that few characters in anime or video games could match up to Professor Oak in terms of how "consistently lovable" he is. Dockery argued that Oak was a particularly noteworthy figure in the franchise's world, citing both how much the Elite Four seems to vie for his attention as well as how, in Gold and Silver, he believed Oak's appearance detracted from the importance of meeting Mr. Pokémon. The New York Times writer Stephanie Strom argued that Professor Oak and Ash Ketchum have the relationship of a sensei and deshi respectively; where the sensei offers "friendship advice and guidance" to the deshi, the deshi responds with "gratitude, respect and loyalty". She also noted that, rather than Oak being responsible for correcting or criticizing Ash, it is Ash's peer group that does. Author Cary Elza described Oak's presence as "one of the show's few true patriarch", noting his character as a balance of both "genius" and "absent-minded". Author Nicholas Raes discussed how Professor Oak compared to his cousin, Samson Oak. He discussed the "strong resemblance", while noting how Samson's differences, such as his clothing, represented the laid-back nature of Alola. He considered this a revamp akin to the regional differences of some Pokémon in Alola compared to other regions, stating that Samson was "re-tooned" to appear more exotic when compared to Oak. On discovering the existence of an official cut battle with Professor Oak, Kotaku writer Patricia Hernandez expressed disappointment, stating that it would have been the perfect way to end Red and Blue. She argued that while defeating the rival may be "cathartic", defeating Oak, who sent the player on the journey in the first place, was a "whole other level of cool". During a livestream of the social experiment Twitch Plays Pokémon in 2015, the cut battle was added into the game using mods, even with added dialogue to acknowledge the Twitch chat.
For the Chicago Bulls' 2023–24 regular-season in September 2023, the team released a schedule video that was themed around Pokémon, designed by the Bulls' digital content and design managers Nikko Tan and Dave Zarzynski. Zarzynski initially created a test run for the video which included the video's intro; the intro is a reference to Professor Oak's introduction, with NBA commissioner Adam Silver appearing to the audience on the screen of a Game Boy as a parody of Oak.