A backlight assembly includes a light source providing light, a mold frame receiving the light source unit and a bottom chassis. The bottom chassis includes a bottom plate, sidewalls extending from the bottom plate and an extension part bent from at least one of the sidewalls and overlapping an adjacent sidewall. The mold frame and the bottom chassis are integrally formed. The extension part overlaps the adjacent sidewall at a corner of the bottom chassis. Thus, the torsional strength of the bottom chassis and a backlight assembly having the bottom chassis is improved. The torsional strength is maintained when a backlight assembly is manufactured.