The present technology relates to a decoding device and a decoding method, and an encoding device and an encoding method that enable images that configure a packed image to be reliably displayed when an encoded stream is decoded and displayed. A decoding unit decodes an encoded data, the encoded data being an encoded packed image in which a plurality of images is packed, and generates the packed image. A display control unit identifies the images that configure the packed image based on packing SEI preferentially used when the packed image is displayed. The present technology can be applied to a decoding device, for example.