A planar light source and a backlight unit including the same are disclosed. The planar light source includes a light emission region formed by arrangements of light emitting devices. The light emission region includes first to nth separate parts each having a center of the light emission region as one vertex (n: natural number of 2 or higher). The first separate part includes light emitting devices arranged two-dimensionally in first and second directions. A pitch in the first direction is different from a pitch in the second direction in at least a portion of the two-dimensional arrangement structure. Light emitting devices of each of the second to nth separate parts have an arrangement structure obtained by a clockwise or counter-clockwise rotation of the arrangement structure of the light emitting devices of the first separate part by an angle of 1/n×360° about the center of the light emission region.