A light source module includes a light guide plate, a light-emitting element, and first and second prism sheets. One of the light-emitting surface and the bottom surface of the light guide plate has strip-shaped microstructures. The bottom surface has bottom microstructures, and the angle between the first surface of each bottom microstructure and the bottom surface is 1° to 17°. The first prism sheet is disposed on the light-emitting surface and between the light-emitting surface and the second prism sheet and includes first prism rods. The second prism sheet includes second prism rods. The aspect ratio of the strip-shaped microstructure is greater than 0.2. The angle between the maximum luminance direction of the light from the light-emitting surface and the normal direction of the light-emitting surface is less than 70°. The light-emitting angle range is less than 40°. A display device including the light source module is also provided.