To improve heat resistance of a polymer having a hetero alicyclic structure obtained by performing cyclization polymerization of α-(allyloxymethyl) acrylates without ruining transparency.

A resin composition includes a polymer (A) that has a repeating unit including a hetero alicyclic structure derived from a monomer shown by formula (1); and a polymer (B) that has a repeating unit shown by formula (2). In addition, the resin composition includes the polymer (A), and a styrene-acrylonitrile copolymer.