Variable inductors, which consist of magnetic core and primary dc and secondary ac windings, can continuously control effective inductance of secondary ac winding by using primary dc current due to the magnetic saturation effect. Variable inductors have advantageous features such as their simple and robust structures, and they are extremely reliable. Therefore, they are suitable in applications as reactive power compensators in electric power systems. A three-phase laminated-core variable inductor was proposed in a previous paper that reduced size and weight more than those in conventional single-phase variable inductors. A novel three-dimensional three-phase variable inductor designed to further reduce size and weight and to improve manufacturing capabilities is presented here. The basic characteristics of the proposed variable inductor were calculated through reluctance network analysis (RNA) and the finite element method (FEM).