A voltage regulator includes a driver transistor, a feedback voltage generator, a reference voltage generator, a first differential amplifier, and a differential gain controller. The driver transistor is connected between input and output terminals to conduct a current therethrough according to a control signal applied to a gate terminal thereof. The feedback voltage generator is connected to the output terminal to generate a feedback voltage. The reference voltage generator generates a reference voltage. The first differential amplifier has an output thereof connected to the gate terminal of the driver transistor, and a pair of differential inputs thereof connected to the feedback voltage generator and the reference voltage generator, respectively, to generate the control signal at the output thereof. The differential gain controller is connected to the output of the first differential amplifier to control the differential gain according to a difference between the input and output voltages.