The present invention provides a polarizing plate for a foldable display free of a risk of causing distortion in an image displayed at a folding portion thereof after being repeatedly folded. The polarizing plate for a foldable display includes: a polarizer; and a polarizer protective film formed of a polyester film laminated on at least one surface of the polarizer, wherein the polyester film satisfies the following conditions: (1) a refractive index in a bending direction is from 1.590 to 1.620; (2) a refractive index in a folding portion direction is from 1.670 to 1.700; (3) a refractive index in a thickness direction is 1.520 or less; and (4) a density is 1.380 g/cm3 or more, wherein the bending direction refers to a direction orthogonal to a folding portion of the polyester film at a time when the polyester film is folded.