A motion vector detection device includes: a matching error calculation part that calculates matching errors between a focus block and each of reference blocks; a least matching error calculation part calculating a least matching error from among the matching errors; a threshold calculation part calculating a threshold value; a correction vector calculation part calculating a correction vector from motion vectors detected in the reference blocks; and a motion vector determination part determining, as a motion vector for the focus block, a relative position vector in a block in which the relative position vector with respect to the focus block is the closest to the correction vector, the block being selected from among the reference blocks in which a difference between the plurality of matching errors and the least matching error is within the threshold value.