It is an object of this invention to provide a retardation film which uses a liquid crystal compound, has a suppressed streak defect and shows a good front contrast, and an application thereof. The present invention provides a retardation film in which a liquid crystal compound capable of showing a smectic phase is fixed in the smectic phase, the retardation film including a non-liquid crystal compound which satisfies the conditions A and B: condition A: molecular weight is 10000 or less; and condition B: T0−T1≤30° C. T0 represents the phase transition temperature between the nematic phase and the isotropic phase of a composition which does not contain the non-liquid crystal compound, and T1 represents the phase transition temperature between the nematic phase and the isotropic phase of a composition which contains the non-liquid crystal compound.