A white polyester film is described that includes at least a layer including, as a main component, a polyester resin (A), a thermoplastic resin (B) incompatible with the polyester resin (A), and an inorganic particle (C), where the white polyester film achieves high reflectance and a concealing property without increasing the thickness of the reflective film, the layer including voids in which the thermoplastic resin (B) functions as nuclei, wherein in a vertical section of the white film, NB2/NB1×100 (%) is 15% or more, wherein NB1 represents the number of the nuclei of the thermoplastic resin (B), and NB2 represents the number of the sections of the thermoplastic resin (B), the sections including the inorganic particle (C) inside.