Thiourea dioxide or thiox is an organosulfur compound that is used in the textile industry.

Crystalline and gaseous thiourea dioxide adopts a structure with C2v symmetry.

[3] Thiourea dioxide was first prepared in 1910 by the English chemist Edward de Barry Barnett.

It has been found that at pH values of less than 2, thiourea and hydrogen peroxide react to form a disulfide species.

[11] Thiourea dioxide has also been used for the reduction of aromatic nitroaldehydes and nitroketones to nitroalcohols.