An illuminator includes a light source that outputs first light, a wavelength converter that converts the first light into second light, an optical element that reflects the first light toward the wavelength converter and transmits the second light, and an illumination system which is disposed on the opposite side of the optical element from the wavelength converter. The wavelength converter includes a substrate, a reflection layer facing a first surface of the substrate, a wavelength conversion layer having a second surface and facing the reflection layer, and a structural element facing the second surface and having a plurality of protrusions that reflect part of the first light. The plurality of protrusions each have an inclining surface that inclines with respect to the second surface, and at least part of the first light and reflected off the inclining surface enters the illumination system without traveling via the optical element.