Disclosed herein is a low noise amplifier having both ultra-high linearity and a low noise characteristic and a radio receiver including the low noise amplifier. The low noise amplifier includes a first main transistor unit, a first auxiliary transistor unit, and an optimum noise and input impedance matching capacitor. The first main transistor unit includes a first NMOS transistor and a first PMOS transistor configured to form a complementary common source amplifier, a feedback-type resistor connected between drains of the first NMOS transistor and the first PMOS transistor and configured to generate biases to the two transistors, and bias resistors connected to bodies of the first PMOS transistor and the first NMOS transistor. The first auxiliary transistor unit includes transistors connected to the two transistors. The optimum noise and input impedance matching capacitor is connected to output terminals of the first main transistor unit and the first auxiliary transistor unit.