There are provided a bias circuit supplying different levels of bias power according to respective power modes through a simple circuit configuration, and a power amplifier having the same. The bias circuit includes: a bias setting unit setting a bias power voltage level by switching reference power having a pre-set voltage level determined according to a pre-set power mode; and a bias supply unit including a switching element performing switching according to the setting of the bias setting unit and supplying bias power having a voltage level determined according to a switching operation of the switching element.