In a high-frequency transformer element includes a primary coil including first coil conductors and a secondary coil including second coil conductors are disposed in a multilayer body that includes a plurality of insulating layers. A magnetic-field cancellation conductor pattern is disposed in the multilayer body, is adjacent to some conductors of the first coil conductors in a lamination direction of the insulating layers, is arranged along a surface of the insulating layers, and allows a high-frequency current to flow in a direction opposite a high-frequency current flowing in the first coil conductors.