Holmium(III) hydroxide is an inorganic compound with the chemical formula Ho(OH)<sub>3</sub>.
Holmium(III) hydroxide reacts with acids to produce holmium(III) salts:
Holmium(III) hydroxide undergoes thermal decomposition to HoO(OH) at elevated temperatures. Further decomposition at higher temperatures produces Ho<sub>2</sub>O<sub>3</sub>.