Thorium(IV) hydroxide is an inorganic compound with a chemical formula Th(OH)4.

Thorium(IV) hydroxide can be produced by reacting sodium hydroxide and soluble thorium salts.

[1] New thorium(IV) hydroxide is soluble in acid but its solubility will decrease when older.

[1] Thorium(IV) hydroxide will break up at high temperature and produce thorium dioxide: At high pressure, thorium(IV) hydroxide reacts with carbon dioxide, and produce thorium carbonate hemihydrate.

[2]