Power amplification system with adjustable common base bias. A power amplification system can include a first transistor having a base coupled to a radio-frequency input. The power amplification can further include a second transistor having an emitter coupled to a collector of the first transistor and having a collector coupled to a radio-frequency output. The power amplification system can include a biasing component configured to apply a fixed biasing signal to the base of the first transistor and to apply an adjustable biasing signal to the base of the second transistor.