Here's a map showing locations of all catchable Pokémon in Omega Ruby & Alpha Sapphire

Hoenn Pokedex by ChrisStarkiller on DeviantArt

Pokémon Omega Ruby and Alpha Sapphire Review – Gone Hoenn

Kaitlyn Molinas on X: Adding to the list of cross-generational Pokemon references, apparently completing the Hoenn-Dex in Omega Ruby/Alpha Sapphire gives you a diploma with a pretty blatant Sun/Moon hint /

Pokemon League - Pokemon Omega Ruby and Alpha Sapphire Guide - IGN

Pokémon Omega Ruby & Alpha Sapphire - DexNav

Ash Ketchum Pokémon X And Y Pokémon Gold And Silver Pokémon Omega Ruby And Alpha Sapphire

Full Sheet View - Pokemon Omega Ruby / Alpha Sapphire - 3rd Generation Pokémon omega ruby and alpha sapphire, Pokemon omega ruby, Omega ruby alpha sapphire

Changes to Hoenn After Ancient Pokemon Battle - Pokemon Omega Ruby and Alpha Sapphire Guide - IGN

Pokémon Omega Ruby/Alpha Sapphire → Pokédex Completion → Hoenn Pokédex Caught

Pokedex Pokémon Omega Ruby and Pokémon Alpha Sapphire No Hoenn