A head-up display includes: a plurality of displays having a plurality of pixels and configured to emit lights from each of the plurality of pixels; a plurality of collimators configured to receive the lights emitted from each pixel of the plurality of pixels of the plurality of displays and output collimated lights by collimating the lights; and a diffractive optical element configured to receive the collimated lights from the plurality of collimators, diffract the collimated lights, emit the collimated lights at angles substantially equal to respective angles at which the collimated lights are incident to the diffractive optical element, respectively, and generate a virtual image by the collimated lights emitted from the diffractive optical element. The head-up display is reduced in size and capable of generating the virtual image at infinity to allow drivers to view the virtual image without shifting their focal point.