A radio frequency power amplifier includes: an amplifying element which amplifies an input signal and outputs the signal from an output terminal; and an output load circuit which includes a first resonant circuit and a second resonant circuit that are connected to the output terminal. The first resonant circuit has a resonance frequency higher than the frequency of the second harmonic of the input signal, and the second resonant circuit has a resonance frequency lower than the frequency of the third harmonic of the input signal. The output load circuit has such an impedance looking from the output terminal that a phase of a reflection coefficient at the second harmonic of the input signal is greater than 180 degrees and less than 360 degrees, and a phase of a reflection coefficient at the third harmonic of the input signal is greater than 0 degrees and less than 180 degrees.