Lead tetroxide, also called minium, red lead or triplumbic tetroxide, is a bright red or orange crystalline or amorphous pigment. Chemically, red lead is lead tetroxide, Pb3O4, or 2PbO·PbO2. This compound's Latin name minium originates from the Minius River in northwest Spain where it was first mined. Natural minium is uncommon, forming only in extreme oxidising conditions of lead ore bodies.

Lead tetraoxide is most often used as a pigment for primer paints for iron objects. Due to its toxicity, its use is being limited. In the past, it was used in combination with linseed oil as a thick, long-lasting anti-corrosive paint. The combination of minium and linen fibres was also used for plumbing, now replaced with PTFE tape. Currently it is mostly used for manufacture of glass, especially lead glass. It finds limited use in some amateur pyrotechnics as a relatively potent oxidizer.