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

Static Encounter: Resolution Cave (Only in Sun & Moon), Ultra Space (Only in Ultra Sun & Ultra Moon)
Walk: Resolution Cave (100%, Only in Sun & Moon)

Guzzlord also appears in

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

Its base catch rate is 15 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 Ultra Ball or Beast Ball.

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