The present invention discloses a generic approach to the design of single-path, switchless multi-resonant, multi-band power amplifiers. In the preferred embodiments, the amplifier includes one or more amplification stages, a switchless, multi-resonant, input impedance network, a switchless, multi-resonant, output impedance network, and if multi-stage, a switchless, multi-resonant, interstage impedance network between each amplification stage. Multi-band amplification is accomplished without the need for externally-applied, frequency-indicating control signals. Moreover, the amplifier may be designed to provide concurrent multi-band amplification or non-concurrent amplification.