Provided are a projection image display member having a high visible light transmittance, suppressing a double image of a display image, and having excellent suitability of polarized sunglasses for incident light reflected from external light, a windshield glass using the projection image display member, and a head-up display system. The problem is solved such that one or more phase difference layers, one or more selective reflection layers, and one or more polarization conversion layers are provided in this order, the polarization conversion layer being a layer in which a helical alignment structure of a liquid crystal compound is fixed, and the number of pitches x of the helical alignment structure and a film thickness y (μm) of the polarization conversion layer satisfying “0.3≤x≤7.0”, “0.5≤y≤6.0”, “y≤0.7x+3.2”, and “y≥0.7x−1.4”.