硫酸铵简称硫铵，化学式为(NH₄)₂SO₄，无色斜方晶体，易溶于水，水溶液为酸性。

硫酸铵是一种氮肥，但对强酸性土壤须同石灰配合施用，在石灰性反应强的土壤上，须深施覆土，以减少氮的损失；也可用作焊药及织物防火剂。

Ammonium sulfate (American English; ammonium tetraoxosulfate (VI) is the IUPAC-recommended spelling; and ammonium sulphate in British English), (NH₄)₂SO₄, is an inorganic salt with a number of commercial uses. The most common use is as a soil fertilizer. It contains 21% nitrogen and 24% sulfur.