Europium(II) hydroxide is an inorganic compound, with the chemical formula of Eu(OH)<sub>2</sub>. It can exist as the dihydrate Eu(OH)<sub>2</sub>÷H<sub>2</sub>O.
The monohydrate of europium(II) hydroxide can be obtained by the reaction of metal europium and 10 mol/L sodium hydroxide solution. There are some sources that use europium(III) chloride as a raw material, and prepare it by reacting the Jones reductor with sodium hydroxide solution.
Europium(II) hydroxide belongs to the orthorhombic crystal system, a=6.701 ñ 0.002, b=6.197 ñ 0.002, c=3.652 ñ 0.001 A. It thermally decomposes to form europium(II) oxide (EuO); it is readily oxidized to europium(III) hydroxide in air.