An illuminator comprising: a light source apparatus that outputs first light that belongs to a first wavelength band; an optical element including a dichroic film having a function of separating polarized components (BLs, BLp) of the first light from each other and a first retardation element, and arranged so that a first component (BLp) of the first light outputted from the light source apparatus sequentially passes through the dichroic film and the first retardation element; a reflection element that reflects the first component having passed through the first retardation element in such a way that the first component passes through the first retardation element again and is reflected off the dichroic film; a light dividing element provided in an optical path of the first component reflected off the dichroic film, the light dividing element including a plurality of lenses; a polarization conversion element including a plurality of polarization converters each including a polarization separation element, a reflection film, and a second retardation element, the polarization conversion element being arranged so that a plurality of light beam fluxes produced by the light dividing element are incident on the corresponding polarization converters; and a wavelength conversion element, wherein: the first light further contains a second component (BLs) that is converted by the wavelength conversion element into second light that belongs to a second wavelength band different from the first wavelength band, the illuminator is arranged so that the second component passes through the dichroic film and is incident on the wavelength conversion element, the wavelength conversion element is arranged so that the second light having exited out of the wavelength conversion element is reflected off the dichroic film and is incident on the light dividing element, and characterized in that the first retardation element is a birefringent substrate and is integral with the dichroic film. a light source apparatus that outputs first light that belongs to a first wavelength band; an optical element including a dichroic film having a function of separating polarized components (BLs, BLp) of the first light from each other and a first retardation element, and arranged so that a first component (BLp) of the first light outputted from the light source apparatus sequentially passes through the dichroic film and the first retardation element; a reflection element that reflects the first component having passed through the first retardation element in such a way that the first component passes through the first retardation element again and is reflected off the dichroic film; a light dividing element provided in an optical path of the first component reflected off the dichroic film, the light dividing element including a plurality of lenses; a polarization conversion element including a plurality of polarization converters each including a polarization separation element, a reflection film, and a second retardation element, the polarization conversion element being arranged so that a plurality of light beam fluxes produced by the light dividing element are incident on the corresponding polarization converters; and a wavelength conversion element, wherein: the first light further contains a second component (BLs) that is converted by the wavelength conversion element into second light that belongs to a second wavelength band different from the first wavelength band, the illuminator is arranged so that the second component passes through the dichroic film and is incident on the wavelength conversion element, the wavelength conversion element is arranged so that the second light having exited out of the wavelength conversion element is reflected off the dichroic film and is incident on the light dividing element, and characterized in that the first retardation element is a birefringent substrate and is integral with the dichroic film. the first light further contains a second component (BLs) that is converted by the wavelength conversion element into second light that belongs to a second wavelength band different from the first wavelength band, the illuminator is arranged so that the second component passes through the dichroic film and is incident on the wavelength conversion element, the wavelength conversion element is arranged so that the second light having exited out of the wavelength conversion element is reflected off the dichroic film and is incident on the light dividing element, and characterized in that the first retardation element is a birefringent substrate and is integral with the dichroic film.