Manganese(II) hydroxide is the inorganic compound with the formula Mn(OH)2.

It is a white solid although samples darken quickly upon exposure to air owing to oxidation.

The Mn(II) centers are bonded to six hydroxide ligands.

Each hydroxide ligand bridges to three Mn(II) sites.

The O-H bonds are perpendicular to the planes defined by the oxygen atoms, projecting above and below these layers.