Cooperite is a grey mineral consisting of platinum sulfide (PtS), general in combinations with sulfides of other elements such as palladium and nickel (PdS and NiS). Its general formula is (Pt,Pd,Ni)S. It is mined as an ore of platinum and platinum group elements such as palladium. It occurs in South Africa in minable quantities and elsewhere.

It is named after R. Cooper who first characterized it in 1928.