Where to find Butterfree in Sun, Moon, Ultra Sun & Ultra Moon

SOS Encounter: Route 5 (30%), Lush Jungle (30%), Melemele Meadow (30%)
Walk: Route 5 (1%), Melemele Meadow (1%)

Butterfree also appears in

How to get Butterfree in Sun, Moon, Ultra Sun & Ultra Moon

Its base catch rate is 45 out of 255 (higher is easier); the catch rate calculator works out your odds with each ball. For the look, the best colour match is Timer Ball, Master Ball or Heal Ball.

Evolution: Caterpie → Metapod (Level 7) → Butterfree (Level 10).

Butterfree in every game · Pokémon Sun, Moon, Ultra Sun & Ultra Moon interactive map (Alola)