A projection image display apparatus includes: a light source; an illumination optical system that uniformly irradiates a surface of an image modulation element serving as a primary image surface with a light beam emitted from the light source; and a projection optical system that enlarges and projects image information on the primary image surface modulated by the image modulation element onto a screen serving as a secondary image surface, and that includes a first optical system that forms an intermediate image from the image information, a single-image second optical system that enlarges and projects the intermediate image to display a single image on the screen, a plural-image second optical system that enlarges and projects the intermediate image to display plural images on the screen, and an optical path switching mechanism that selectively guides a light beam from the first optical system to the single-image or plural-image second optical system.