The present invention relates to an encoding apparatus and an encoding method capable of reducing the overhead on a macroblock basis. A number of reference image decision unit 19 determines that the number of fields of the reference image in encoding is one on the basis of the bit rate of the coded data. If the number of fields of the reference image is determined to be one, a slice header generating unit 13 selects, from among pictures input to an image sorting buffer 12, one of the pictures as the reference image. The present invention is applicable to, for example, encoding apparatuses that perform video coding based on the AVC standard.