The present invention addresses the problem of providing a polyester resin composition for reflective materials which gives a reflective material having a high reflectance. The polyester resin composition for reflective materials comprises: a polyester resin (A) comprising an alicyclic dicarboxylic acid ingredient unit (a1) and an aliphatic diol ingredient unit (b1); and a white pigment (B). The amount of the alicyclic dicarboxylic acid ingredient unit (a1) is 50 mol % or more of the amount of all the dicarboxylic acid ingredient units (a) in the polyester resin (A), and the amount of the aliphatic diol ingredient unit (b1) is 50 mol % or more of the amount of all the diol ingredient units (b) in the polyester resin (A). The alicyclic dicarboxylic acid ingredient unit (a1) comprises the cis and trans forms of cis-trans isomers, the proportion of the cis form determined by NMR being 20 mol % or higher.