Provided is a light source device including: a housing body; a light source substrate located over and accommodated in the housing body; a plurality of inorganic light-emitting elements over the light source substrate; an optical sheet located over the plurality of inorganic light-emitting elements, accommodated in the housing body, and spaced away from the light source substrate; and at least one spacer accommodated in the housing body and in contact with a bottom surface of the optical sheet. A region of an upper surface of the light source substrate overlapping the plurality of inorganic light-emitting elements does not overlap the at least one spacer.