A filter circuit includes an antenna-side circuit, a transmission-side circuit, a reception-side circuit, and an external connection capacitor. The antenna-side circuit is connected to an antenna-side terminal. The transmission-side circuit is connected to a transmission-side terminal and the antenna-side circuit. The reception-side circuit is connected to a reception-side terminal, the antenna-side circuit, and ground. The external connection capacitor is connected between an external control terminal and a connection point between the antenna-side circuit and the reception-side circuit. The antenna-side circuit and the transmission-side circuit constitute a low pass filter. The antenna-side circuit and the reception-side circuit constitute a band pass filter. The reception-side circuit includes an LC parallel resonant circuit.