A coupling compensator for a display panel and a display device including the coupling compensator are disclosed. In one aspect, the coupling compensator includes a memory configured to receive grayscale data and store the grayscale data and a first data converter configured to convert the grayscale data to a plurality of grayscale data voltages including first and second grayscale data voltages. The compensator also includes a coupling voltage calculator configured to calculate a line coupling voltage generated on a data line based on the difference between the first grayscale data voltage corresponding to the grayscale data provided to a first group of the pixels in an (N−1)th row and the second grayscale data voltage corresponding to the grayscale data provided to a first group of the pixels in an Nth row, where the N is an integer equal to or greater than 2.