Provided is a liquid crystal display device. The liquid crystal display device includes a first sub-pixel configured to represent any one of red, green, and blue; a second sub-pixel adjacent to the first sub-pixel and configured to represent a different color from the first sub-pixel; and a black matrix disposed underneath along a boundary between the first sub-pixel and the second sub-pixel and configured to have a particular width that suppresses color mixture between the first sub-pixel and the second sub-pixel.