A curved display device includes a first substrate, a pixels and a second substrate. The first substrate is curved along a first direction and includes a pixel area through which light is transmitted and a non-pixel area which blocks light transmission therethrough. The pixel is disposed in the pixel area. The second substrate is curved along the first direction, and is opposite to and coupled to the first substrate. First trenches are defined in at least one substrate among the first and second substrates and extending in a second direction intersecting the first direction.