Abstract: Provided are a method for three-dimensionally molding a film, a method for manufacturing a film molded body, and a film molded body that make it possible to easily perform three-dimensional molding of an inner film portion while achieving a reduction in processing time and a decrease in energy consumption and without requiring a design change to the existing equipment. A method for three-dimensionally molding a film, the method including performing cold compression molding in a thickness direction on a film overlapping section in which at least one inner film portion including a first layer and a second layer having an elongation smaller than that of the first layer is arranged between two outer film portions in a non-fixed state with respect to the outer film portions, thereby causing the inner film portion to protrude toward the second layer side at the film overlapping section.