A chip on film and a display device including the same selectively outputs gate transmission signals and data outputs to reduce the number of output pads in a data driving IC. The COF includes first to third groups of data input pads, gate input pads, and output pads. A data driving IC includes first to third groups of output buffers, a first switchable output unit configured to selectively supply gate transmission signals and an output of the first group of output buffers to the first group of output pads, and a second switchable output unit configured to selectively supply the gate transmission signals and an output of the third group of output buffers to the third group of output pads. An output of the second group of output buffers is supplied to the second group of output pads between the first and the third groups of output pads.