A gamma control data mapping circuit, a mapping method, and a display device using the gamma control data mapping circuit are provided. The gamma control data mapping circuit is for converting input data into grayscale data to display an original image on a display device. The mapping circuit separates the input data into high-order bit data and low-order bit data, and outputs a low-order grayscale boundary and a high-order grayscale boundary by using the high-order bit data. The gamma control data mapping circuit divides a grayscale region defined by the low-order grayscale boundary and the high-order grayscale boundary by a unit grayscale number to calculate unit grayscale data of the grayscale region, multiplies the low-order bit data by the unit grayscale data to calculate linear grayscale data, and adds the low-order grayscale boundary to the linear grayscale data to generate the grayscale data.