Pokémon Legends: Arceus is a 2022 action role-playing game developed by Game Freak and published by Nintendo and The Pokémon Company for the Nintendo Switch. It is part of the eighth generation of the Pokémon video game series and serves as a prequel to Pokémon Diamond and Pearl (2006). The game was first announced as part of the Pokémon 25th Anniversary event in February 2021, and was released worldwide on 28 January 2022.

The game follows the protagonist, sent back through time, as they travel through the Hisui region based on the island of Hokkaido during early Japanese colonization. Centered around exploration of the region's several open areas populated with Pokémon, the game's objective is to complete a roster of the region's Pokémon, known as the Pokédex. Pokémon Legends: Arceus was a commercial success, having sold over 13.91 million copies by September 30, 2022. Pokemon Legends: Arceus was a critical success, receiving generally favourable reviews, and being nominated for several end of the year awards, including Best RPG at The Game Awards.

Pokémon Legends: Arceus was first revealed in the Pokémon Presents on 26 February 2021 alongside Pokémon Brilliant Diamond and Shining Pearl as part of the Pokémon 25th Anniversary celebration.  According to the official Pokémon Twitter account, it serves as a "premake" to Diamond and Pearl. During a Pokémon Presents on 18 August 2021, new trailer was revealed with a focus on exploration and story background, as well as new Pokémon. On 28 September 2021, a new trailer showcased some of the game's customization, menus, characters, and Kleavor, a new Pokémon. On 19 October 2021, an artificially corrupted "found footage" CGI video was showcased teasing new Pokémon.  Two days later, it was confirmed that the obscured Pokémon were regional forms of Zorua and Zoroark. On 9 December 2021, the official Pokémon Twitter account teased a Poké Ball-related announcement for Legends: Arceus. The next day, a regional variant of Voltorb, a Pokémon based on Poké Balls, was announced.  On 15 December 2021, a new trailer showcased several factions present in the game, as well as their leaders. On 7 January 2022, an overview trailer was released in Japanese, showcasing the world, people, and Pokémon. However, the trailer was not localized into English until 24 January 2022.

The game was released worldwide on 28 January 2022. Exclusive in-game and physical bonuses were given out to those who pre-ordered the game digitally or physically. In Japan, those who pre-ordered Pokémon Legends: Arceus received a gold holographic artbook along with a limited edition Arceus promotional trading card.

The game is set in a bygone era of the Sinnoh region's history, when it was known as the Hisui region, long before the events of Pokémon Diamond and Pearl and their remakes take place. Hisui is based on the real-life island of Hokkaido during the Muromachi period, when it was still known as Ezo, with new settlers from other regions interacting with natives in a parallel with the interaction between Hokkaido's Ainu people and Japanese settlers. Ainu groups are represented in the game by the Diamond and Pearl clans, while new mainland settlers are represented by the Galaxy Expedition Team.

The vast majority of the region is covered in sparse, open wilderness populated with wild Pokémon, with only one significant settlement in addition to a number of small campsites. Unlike in the setting of previous Pokémon games,