A copper alloy disclosed in the present description has a basic alloy composition represented by Cu100−(x+y)SnxAly (where 8≤x≤12 and 8≤y≤9 are satisfied), in which a main phase is a βCuSn phase with Al dissolved therein, and the βCuSn phase undergoes martensitic transformation when heat-treated or worked. A method for producing a copper alloy disclosed in the present description is a casting step of melting and casting a raw material containing Cu, Sn, and Al and having a basic alloy composition represented by Cu100−(x+y)SnxAly (where 8≤x≤12 and 8≤y≤9 are satisfied) so as to obtain a cast material, and a homogenization step of homogenizing the cast material in a temperature range of a βCuSn phase so as to obtain a homogenized material, the method includes at least the casting step.