What was the first Pokémon theatrical film called?

The first Pokémon theatrical film was Pokémon: The First Movie.

The 1998 Japanese film is commonly presented in English as Pokémon: The First Movie—Mewtwo Strikes Back. It was directed by Kunihiko Yuyama and centers on Mewtwo, a genetically engineered Pokémon who questions its origin and challenges humans and other Pokémon.

The Japanese theatrical release took place on July 18, 1998. The English-language version reached North America in November 1999 through Warner Bros. Pictures. Its theatrical program also included the short Pikachu's Vacation, which helped establish the tradition of pairing feature stories with Pikachu adventures.

The movie is often called simply Mewtwo Strikes Back, but Pokémon: The First Movie is the standard English title for the original theatrical feature. It is distinct from Pokémon: Mewtwo Strikes Back—Evolution, a computer-animated remake released in 2019.