A power source circuit includes a linear regulator including: an amplifier configured to amplify an envelope signal for representing an envelope of an input signal input into a power amplifier, and an output stage including transistors, configured to output power output to be supplied to the power amplifier in accordance with amplified output of the amplifier; a monitor circuit configured to monitor the envelope signal; and a switched-capacitor circuit configured to generate a power source voltage higher than a voltage of the power output based on a monitoring result of the monitor circuit, wherein the switched-capacitor circuit does not supply the power source voltage to the amplifier, but supplies the power source voltage to the output stage.