过硫酸钾，化学式K₂S₂O₈。

过硫酸钾为无色或白色细小粉末、或片状三斜结晶，溶于水，不溶于醇，水溶液呈酸性。熔度为100°C，并生成焦硫酸钾。室温情况下，水溶液会缓慢分解生成过氧化氢，呈强氧化性。与有机物混合，可引发爆炸。

Not to be confused with potassium peroxymonosulfate.

Potassium persulfate is the inorganic compound with the formula K₂S₂O₈. Also known as potassium peroxydisulfate or KPS, it is a white solid that is highly soluble in water. This salt is a powerful oxidant, commonly used to initiate polymerizations.