Azurill's evolutions, Marill and Azumarill, are the only Pokémon with the Water and Fairy-type combination in Pokémon Scarlet and Violet. Azurill can be encountered fairly early as you start your journey in Paldea, but it has a unique evolution method. This may leave you wondering how to evolve Azurill into Marill in Pokémon Scarlet and Violet.
How to get Marill in Pokémon Scarlet & Violet
To evolve Azurill into Marill, you must increase Azurill's friendship. Once you have raised Azurill's friendship high enough, you will be able to evolve. Simply level it up, and it will evolve into Marill. If you do not have a high enough friendship with Azurill, it will not evolve.
How to raise friendship quickly in Pokémon Scarlet & Violet
Your Azurill's friendship will increase over time naturally, but you can further increase it to get it to evolve quicker. The best way to increase friendship fast is by setting up picnics. While doing this, you can feed Azurill sandwiches, play with it, and give it a bath. You can also raise its friendship with certain berries, but these will also decrease its stats, making picnics the better option.
Another way to increase your friendship with Azurill, give it the Soothe Bell. This held item boosts the rate at which friendship grows. If you want to know what your friendship is, go to Cascarrafa and check its friendship level. This NPC is in the main plaza standing next to a Marill.
For more information on Pokémon Scarlet & Violet, check out How to evolve Igglybuff into Jigglypuff in Pokémon Scarlet & Violet and How to evolve Pichu into Pikachu in Pokémon Scarlet & Violet on Pro Game Guides.