A heat-shrinkable white polyester film is provided which has extremely satisfactory cuttability along a perforation and has light-shielding properties. Also provided are: a label; and a process for producing the film with high productivity. The heat-shrinkable white polyester film comprises a polyester resin constituted of ethylene terephthalate as a main constituent component and containing at least 13 mol % one or more monomer ingredients capable of serving as an amorphous component among all components of the polyester resin. This film has specific heat shrinkability, specific light-shielding properties, and specific mechanical properties. The process is excellent in the productivity of the film. The label is obtained from the heat-shrinkable white polyester film.