This Justin Bieber photo contains
fedora, felt hat, homburg, stetson, trilby, hip boot, thigh boot, boater, leghorn, panama, panama hat, sailor, skimmer, and straw hat.
There might also be
dress hat, high hat, opera hat, silk hat, stovepipe, top hat, topper, beaver, well dressed person, suit, pants suit, pantsuit, beaver, and castor.