A power amplifying circuit includes an amplifier that amplifies a radio-frequency signal and a bypass capacitor section connected to a power supply terminal for supplying a power supply voltage to the amplifier. The bypass capacitor section includes a first capacitor, a second capacitor, and a first switch circuit. The first capacitor includes a first end connected to a power supply path, and a second end. The second capacitor includes a first end connected to the second end of the first capacitor and a second end connected to ground. The first switch circuit includes a first terminal connected to the second end of the first capacitor and the first end of the second capacitor, and a second terminal connected to the ground. The first switch circuit switches between connection and non-connection between the second end of the first capacitor and the ground.