Provided are a light source module and a backlight unit (BLU) including the same. The light source module includes a substrate including a base plate extending in a first direction and a pair of dam structures stacked on opposing sides of the base plate along a second direction, orthogonal to the first direction, and extending along the base plate in the first direction, wherein the pair of dam structures are spaced apart from each other along a third direction, orthogonal to the first and second directions. A plurality of light-emitting devices are mounted on the substrate between the pair of dam structures and spaced apart from one another in the first direction. An encapsulation layer covers at least one side surface and a top surface of each of the plurality of light-emitting devices. A height of the pair of dam structures is greater than a height of the encapsulation layer.