A backlight assembly comprises: a receptacle; a support frame; and a light source module. The support frame is arranged on one side of the receptacle. The light source module is accommodated in the support frame and includes a printed circuit board and light sources. The support frame includes: a bottom portion; a side wall portion; a cover portion; a gap holding portion; and an insertion groove. The side wall portion extends from the bottom portion. The cover portion extends from the side wall portion to an inside. The gap holding portion extends from an end portion of the cover portion in a direction of the bottom portion. The printed circuit board is partially inserted into the insertion groove to be arranged on the upper surface of the bottom portion. The light sources are surrounded by the side wall portion, the cover portion, and the gap holding portion.