Optical films are provided for which the retardation generated, and the wavelength dispersion of that retardation, are able to be controlled. (1) An optical film containing a thermoplastic norbornene resin with a photoelastic coefficient (C_P) within a range from 0 to 100 (10^-12 Pa^-1), and a stress optical coefficient (C_R) within a range from 1500 to 4000 (10^-12 Pa^-1). (2) An optical film containing a thermoplastic norbornene resin either with a group represented by the general formula (2), shown below, or with at least one group selected from the general formulas (3) and (4) shown below. —(CH₂)_p—O—C(O)—R⁵ ##STR1##