Lugol's iodine, also known as Lugol's solution, is a solution of iodine named for J.G.A. Lugol, French physician. Lugol's iodine solution is often used as an antiseptic and disinfectant.

It consists of 5% iodine (I₂) and 10% potassium iodide (KI) in distilled water. Potassium iodide is added to render the iodine water-soluble.