Breithauptite is a nickel antimonide mineral with the simple formula NiSb.

It is typically massive to reniform in habit, but is observed as tabular crystals.

It occurs in hydrothermal calcite veins associated with cobalt–nickel–silver ores.

It was first described in 1840 from the Harz Mountains, Lower Saxony, Germany, and in 1845 for occurrences in the Cobalt and Thunder Bay districts of Ontario, Canada.

It was named to honor Saxon mineralogist Johann Friedrich August Breithaupt (1791–1873).