A display device includes: a display panel; a lower frame including a bottom portion and side portions; a light source unit extending along a first side portion of the lower frame; a light guide plate including a light opposing surface opposing a light incident surface in a first direction; a first auxiliary frame in the lower frame to restrict movement of the light incident surface in the first direction; a second auxiliary frame fixable to the bottom portion of the lower frame to restrict movement of the light opposing surface in the first direction; and a coupling member with which the second auxiliary frame is fixed to the lower frame. The second auxiliary frame includes a through hole through which the coupling member is extendable, and a width of a head portion of the coupling member is larger than a width of the through hole.