A foldable display device includes a display panel, a folding line extending in a first direction, a first non-folding area disposed on a first side of the folding line and which extends in a second direction perpendicular to the first direction, a second non-folding area disposed on a second side of the folding line opposite the first side and which extends in the second direction, and a through hole defined in the first non-folding area and which penetrates the display panel in a thickness direction. In a plan view, a first maximum width of the through hole in the first direction is smaller than a second maximum width of the through hole in the second direction.