氧化镱，化学式Yb₂O₃。

纯品为白色粉末，含有少量氧化钍时则呈黄褐色。不溶于水和冷酸，溶于温稀酸。

Ytterbium(III) oxide is the chemical compound with the formula Yb₂O₃. It is one of the more commonly encountered compounds of ytterbium. It has the "rare-earth C-type sesquioxide" structure which is related to the fluorite structure with one quarter of the anions removed, leading to ytterbium atoms in two different six coordinate (non-octahedral) environments.