A data driver includes a first data voltage generator, a data converter and a second data voltage generator. The first data voltage generator is configured to generate a first data voltage based on first pixel data and configured to output the first data voltage to a first data line, the first pixel data being generated based on a first gamma curve. The data converter is configured to convert second pixel data to first converted pixel data, the second pixel data being generated based on the first gamma curve, the first converted pixel data being generated based on a second gamma curve different from the first gamma curve. The second data voltage generator is configured to generate a second data voltage based on the first converted pixel data and configured to output the second data voltage to a second data line.