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

Only in Moon & Ultra Moon
Static Encounter: Haina Desert (Only in Moon), Malie Garden (Only in Moon), Ultra Space (Only in Ultra Moon)
Walk: Haina Desert (100%, Only in Moon), Malie Garden (100%, Only in Moon)

Celesteela also appears in

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

Its base catch rate is 25 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 Nest Ball or Beast Ball.

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