Erbium sulfate (also called Erbium Sulphate) is the sulfate of trivalent erbium with the chemical formula Er₂(SO₄)₃. It is soluble in water, and readily soluble in strong mineral acids. The most common form is octahydrate. 

Erbium Sulfate is an important colorant in glass manufacturing and porcelain enamel glazes. High purity Erbium Sulfate is applied as dopant in making optical fiber and amplifier. It is particularly useful as an amplifier for fiber optic data transfer.