A light source device includes first to third light sources, a fluorescent material, and a dichroic mirror. The dichroic mirror is constituted so that excitation light emitted from the first light source is transmitted through the dichroic mirror and applied to the fluorescent material, light of a first wavelength bandwidth emitted from the second light source is transmitted through the dichroic mirror and emitted in a predetermined emitting direction, generated light emitted from the fluorescent material is reflected by the dichroic mirror and emitted in the predetermined emitting direction, and at least a part of light of a second wavelength bandwidth from the third light source passes the outside of the dichroic mirror without entering the dichroic mirror, and is emitted in the predetermined emitting direction.