A data driver includes a first and second data voltage generator and a third data voltage generator. The first and second data voltage generator generates a first data voltage corresponding to a first grayscale value and a second data voltage corresponding to a second grayscale value lower than the first grayscale value based on a reference voltage. The third data voltage generator generates a third data voltage corresponding to a third grayscale value lower than the second grayscale value based on a voltage level difference between the first data voltage and the second data voltage.