Berkelium(III) oxide is a binary inorganic compound of berkelium and oxygen with the chemical formula .
Berkelium(III) oxide can be prepared from berkelium(IV) oxide by reduction with hydrogen:
The compound forms a yellow-green solid with a melting point of 1920 ðC. It forms a body-centered cubic crystal lattice with a = 1088.0 ñ 0.5 pm.
Insoluble in water.