Antimony (Sb) is a chemical element with atomic number 51. It is called stibium in Latin, hence the symbol Sb.

The largest industrial use of antimony is in flame-proofing materials, where antimony trioxide (Sb₂O₃) is added to things like plastics and textiles to make them less flammable.

There are two stable antimony isotopes, ¹²¹Sb and ¹²³Sb, and ¹²¹Sb is the more abundant of the two.