A bicycle disc brake rotor is provided that has a center rotational axis, and basically includes an outer portion and a cooling fin. The outer portion includes a first braking part defining a first braking surface and a second braking part defining a second braking surface. The first and second braking surfaces face in opposite axial directions. The cooling fin includes an inner portion radially offset from the first and second braking surfaces. The cooling fin further includes an attachment portion extending outwardly from the inner portion and sandwiched between the first and second braking parts. The first and second braking parts are separate and distinct individual parts from each other and from the cooling fin.