A phase difference film layered body is obtained by stretching a film before stretching, the film before stretching including: a P1 layer formed of a resin p1 containing polyphenylene ether having a positive intrinsic birefringence value and a polystyrene-based polymer having a negative intrinsic birefringence value and having a syndiotactic structure; and a P2 layer disposed in contact with the P1 layer and formed of a resin p2 containing an acrylic resin or an alicyclic structure-containing polymer. In the resin p1, the weight ratio of (the content of the polyphenylene ether)/(the content of the polystyrene-based polymer) is 35/65 to 45/55. A method for producing the phase difference film layered body and a method for producing a phase difference film using the phase difference film layered body are also provided.