A case assembly and a wireless communication device are provided. The case assembly includes a metal case and a plastic cladding body. The metal case includes an inner side and an outer side, the inner side is opposite to the outer side, the metal case includes a hollow portion and an antenna portion, the hollow portion is adjacent to a side of the antenna portion. The plastic cladding body is disposed on the metal case, and completely covers the outer side of the metal case, partially covers the inner side of the metal case, and fills the hollow portion. The wireless communication device includes a case assembly and a radio frequency signal module. The radio frequency signal module is electrically connected to the antenna portion of the case assembly. Thus, the structural rigidity of the wireless communication device and its case assembly is kept, and the production cost is reduced.