A triple cascode power amplifier is provided. The triple cascode power amplifier includes a first-stage transistor pair, a second-stage transistor pair and a third-stage transistor pair. The first-stage transistor pair comprises two first-stage transistors that respectively receive two dynamic bias voltages with opposite polarities. The second-stage transistor pair is coupled with the first-stage transistor pair to form a first node and comprise two second-stage transistors coupled with each other to form a second node. The third-stage transistor pair is coupled with the second-stage transistor pair and comprises two third-stage transistors for outputting a differential signal. The first-stage transistor pair and the second-stage transistor pair are low voltage components while the third-stage transistor pair is a high voltage component. The power amplifier transforms the differential signal into a single-ended signal for output.