A composite LC resonator includes a ground electrode adjacent to a first principal surface of a multilayer body, a first capacitor electrode farther inward than the ground electrode and defining a first capacitor together with the ground electrode, a first electrode of a second capacitor, a second electrode of the second capacitor defining a second capacitor together with the first electrode of the second capacitor, a first via-electrode defining a first inductor, a first end of the first via-electrode electrically connected to the first capacitor electrode and a second end of the first via-electrode electrically connected to the first electrode of the second capacitor, and a second via-electrode defining a second inductor, a first end of the second via-electrode electrically connected to the second electrode of the second capacitor and a second end of the second via-electrode being electrically connected to the ground electrode.