From Bulbapedia, the community-driven Pokémon encyclopedia.
Unshō Ishizuka (Japanese: 石塚運昇 May 16, 1951 – August 13, 2018) was a Japanese voice actor for the Pokémon anime.
Ishizuka was born on May 16, 1951, in Katsuyama, Fukui, Japan. He became a voice actor in 1984, becoming known for his deep, strong voice, which led to him being typecast as older and more mature male characters. His most notable roles in the Pokémon anime are that of Professor Oak and the unseen narrator. He died on August 13, 2018 of esophageal cancer. However, he managed to record his parts for episodes all the way to October. Following his death, archive audio for Ishizuka has been used for Sophocles's Charjabug, Toucannon, and Tapu Bulu. His prerecorded narration was featured posthumously in M22.
* This song is credited in-character as Professor Oak.
Other non-Pokémon roles
Note: In the case of dubbing roles, the name of the character and TV show/movie/franchise are followed by the original English actor's name in parentheses.