What is the English title of the first Pokémon theatrical film, released in Japan in 1998?

The first Pokémon theatrical film is titled Pokémon: The First Movie.

The film was released in Japan on July 18, 1998, under the subtitle Mewtwo Strikes Back. It was directed by Kunihiko Yuyama and produced as the first feature in the Pokémon anime film series. Its story centers on Mewtwo, a genetically engineered Pokémon who challenges human ideas about creation, identity, and power.

Ash, Misty, and Brock are invited to New Island by a mysterious Pokémon Trainer. There they encounter Mewtwo and cloned Pokémon, leading to a confrontation between original and copied creatures. The theatrical release also included the short film Pikachu's Summer Vacation.

English-speaking audiences commonly call it Pokémon: The First Movie, while Mewtwo Strikes Back is the subtitle used in the full English title. It should not be confused with Pokémon: Mewtwo Strikes Back—Evolution, the computer-animated remake released in 2019.