Which Pokémon video game first introduced the Hoenn region?

Pokémon Ruby and Sapphire first introduced the Hoenn region.

Released for the Game Boy Advance in Japan in 2002, Ruby and Sapphire began Pokémon’s third generation. Their new region is made up of mainland areas and islands, with a geography influenced by the Japanese island of Kyushu.

The games introduced more than 100 new Pokémon, alongside features such as double battles, Pokémon Contests, natures, abilities, and secret bases. Their two villainous teams, Team Magma and Team Aqua, pursue opposing plans involving land and sea.

Gold and Silver introduced Johto, while Diamond and Pearl later introduced Sinnoh. These regional names identify different generations rather than alternate names for the same map.