An image pickup apparatus includes an image-pickup optical system, three color separation prisms separating incident light guided by the image-pickup optical system into three-primary-color light components and emitting the light components, and three image pickup elements respectively receiving the three light components from the prisms so as to produce respective image signals. Of the three prisms, a first prism that first receives the incident light has an edge extending parallel to an incidence plane. The image-pickup optical system has a plate-like fixed aperture stop disposed between the first prism and a final lens, disposed closest to the first prism, of multiple lenses included in the image-pickup optical system. The fixed aperture stop has an aperture that limits the incident light. An edge section of the aperture has projections and depressions arranged at least in parallel to the edge, as viewed from an optical-axis direction of the final lens.