The invention provides a light source device and a projector, wherein the light source device can emit anticipated light. The light source device includes a solid-state light source, a collimator lens which a light beam emitted from the solid-state light source enters, an afocal optical system which includes a light collecting optical system and a collimating optical system and which the light beam having been transmitted through the collimator lens enters, a lens integrator which the light beam having been transmitted through the afocal optical system enters, a polarization splitting element which the light beam having been transmitted through the lens integrator enters, and a wavelength conversion element which a first polarization component split by the polarization splitting element from the light beam enters. At least one of the light collection optical system and the collimating optical system includes a lens formed of quartz.