A stretchable display device (100, 400, 600, 800), comprising: a lower substrate having a plurality of first areas, wherein adjacent ones of the first areas are spaced apart from one another, a plurality of second areas adjacent the first areas, and a plurality of third areas other than the first areas and the second areas, the third areas being surrounded by the first areas and the second areas, a plurality of island substrates respectively disposed in the first areas of the lower substrate and being more rigid than the lower substrate, a plurality of sub-pixels being defined on the island substrates, wherein each of the sub-pixels includes a light-emitting element, a plurality of connection substrates being arranged in the second areas and between the island substrates, a plurality of connection lines, the plurality of connection lines being disposed on the connection substrates and electrically connecting adjacent ones of the island substrates, characterized by a plurality of additional sub-pixels (SPXA) being defined in the third areas, each of the additional sub-pixels (SPXA) including an additional light-emitting element; and a plurality of piezoelectric patterns disposed in the third areas, each of the piezoelectric patterns electrically connected to a respective one of the additional sub-pixels (SPXA), and configured such that, when the stretchable display device is stretched by an external force, mechanical energy is applied to the piezoelectric patterns from the external force and electric energy is generated from the piezoelectric patterns and provided to the additional light-emitting elements so that they emit light simultaneously as the stretchable display device is stretched. a lower substrate having a plurality of first areas, wherein adjacent ones of the first areas are spaced apart from one another, a plurality of second areas adjacent the first areas, and a plurality of third areas other than the first areas and the second areas, the third areas being surrounded by the first areas and the second areas, a plurality of island substrates respectively disposed in the first areas of the lower substrate and being more rigid than the lower substrate, a plurality of sub-pixels being defined on the island substrates, wherein each of the sub-pixels includes a light-emitting element, a plurality of connection substrates being arranged in the second areas and between the island substrates, a plurality of connection lines, the plurality of connection lines being disposed on the connection substrates and electrically connecting adjacent ones of the island substrates, characterized by a plurality of additional sub-pixels (SPXA) being defined in the third areas, each of the additional sub-pixels (SPXA) including an additional light-emitting element; and a plurality of piezoelectric patterns disposed in the third areas, each of the piezoelectric patterns electrically connected to a respective one of the additional sub-pixels (SPXA), and configured such that, when the stretchable display device is stretched by an external force, mechanical energy is applied to the piezoelectric patterns from the external force and electric energy is generated from the piezoelectric patterns and provided to the additional light-emitting elements so that they emit light simultaneously as the stretchable display device is stretched.