This is an index of all of the towns and cities in Hoenn, the region you play in on Pokémon Omega Ruby. You may edit this page if there is more you want to add.
LITTLEROOT TOWN Edit
This is where you new house is at the start of the game. Professor Birch, who you will meet later on in the game, is based here and also lives here. This is the only town (or city) in Hoenn that doesn't have a Pokémon Centre.
Route 101 is the route that connects Littleroot Town and Oldale Town. This is the place you meet Professor Birch in.
OLDALE TOWN Edit
Oldale Town is the first town you'll meet that has a Pokémon Centre and a Poké Mart. Upon entering Oldale, you will meet a Poké Mart clerk, who will give you ten free Potions. The clerk will also show you where the Pokémon Centre is and also where the Poké Mart is.