A duty cycle correction circuit includes a signal generating unit including a first signal generating unit coupled to a power supply voltage terminal and configured to output a complementary output signal of an output signal in response to a clock signal, and a second signal generating unit coupled to the power supply voltage terminal and configured to output the output signal in response to a complementary clock signal of the clock signal; a variable resistor unit coupled between the first and second signal generating units configured to vary an amount of current flowing into the signal generating unit according to a duty correction control signal, the duty correction control signal having a voltage level determined based on a voltage level of the output signal; and a current source coupled between the variable resistor unit and a ground voltage terminal configured to supply current to the signal generating unit.