To provide a liquid crystal display device that is uniformly irradiated with light from a backlight, when the cost of the device is suppressed by reducing the number of light sources.

The liquid crystal display device includes a liquid crystal panel LP having a display region DP for displaying an image, a linear light-emitting unit IL linearly extending and disposed below the display region DP, and a diffusion plate DB disposed between the liquid crystal panel LP and the linear light-emitting unit IL. The diffusion plate DB has a thick portion DBa formed to be thicker than other portion below the display region DP, and the thick portion DBa is formed opposing to the linear light-emitting unit IL.