When did the first season of the Pokémon anime begin airing in Japan?

The first season of the Pokémon anime began airing in Japan on April 1, 1997.

Known internationally as Pokémon: Indigo League, the season originally aired simply as Pokémon in Japan. TV Tokyo broadcast it from April 1, 1997, until January 21, 1999. Its opening episode introduced Ash Ketchum and his reluctant partner Pikachu.

The Japanese season contained 82 episodes, while the English version contained 80. The difference resulted from broadcast and adaptation choices, including the handling of an episode that was not initially shown in several countries after the 1997 Pokémon broadcast incident.

The series later spread internationally. It began airing in the United States in first-run syndication in September 1998, more than a year after its Japanese debut. That delay sometimes leads people to give the American premiere as the anime's start date, but the franchise's television debut occurred in Japan in 1997.