Provided is a transparent conductive polyester film for a foldable display which is free of occurrence of a fold mark or a tear at a folding portion thereof to be used in a foldable display excellent in mass productivity, and free of a risk of causing distortion in an image displayed at a folding portion thereof, and a mobile device. The transparent conductive polyester film for a foldable display includes: a polyester film; and a transparent conductive layer laminated on at least one surface of the polyester film, 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.