Arceus (Japanese: アルセウス Arceus) is a Normal-type Mythical Pokémon introduced in Generation IV.

While it is not known to evolve into or from any other Pokémon, Arceus will change type when it is holding a Plate or type-specific Z-Crystal.

Like Darkrai and Shaymin before it, Arceus was not officially recognized by Nintendo until February 14, 2009, the year of its debut movie. It was officially revealed to international audiences on August 3, 2009.

Arceus is known as "The Original One", as it is said that it created Sinnoh and Ransei, and possibly the entire Pokémon universe, along with the lake guardians and creation trio.

It is the trio master of both the lake guardians and the creation trio.

Arceus is featured prominently in Pokémon Legends: Arceus and plays a major role in its plot.