An impedance matching circuit with at least one tunable notch filter for a power amplifier is disclosed. The power amplifier amplifies an input radio frequency (RF) signal and provides an amplified RF signal. The impedance matching circuit performs output impedance matching for the power amplifier and includes at least one tunable notch filter. Each tunable notch filter has a notch that can be varied in frequency to provide better attenuation of an undesired signal. The at least one tunable notch filter attenuates at least one undesired signal in the amplified RF signal. The at least one tunable notch filter may include (i) a first tunable notch filter to attenuate a first undesired signal at a second harmonic of the amplified RF signal and/or (ii) a second tunable notch filter to attenuate a second undesired signal at a third harmonic of the amplified RF signal.