Provided is a voltage regulator configured to suppress a fluctuation in output voltage even when a power supply voltage fluctuates, thereby realizing stable operation thereof. The voltage regulator includes a control circuit including a first input terminal connected to a drain of an output transistor, a second input terminal connected to a power supply terminal, an overshoot detection circuit connected to the first input terminal, and a power supply voltage detection circuit connected to the second input terminal, and being configured to cause a boost current to flow through an error amplifier circuit when an output voltage and a power supply voltage largely fluctuate with respect to a predetermined voltage.