There is provided a period estimation apparatus including: a first frequency estimation unit that estimates a first frequency of a one-dimensional signal on the basis of a phase difference between the one-dimensional signal and a reference signal and a temporal change in the phase difference； and a second frequency estimation unit that estimates a second frequency of the one-dimensional signal by cutting out a comparative signal having a section length equivalent to a first period corresponding to the first frequency from the one-dimensional signal, and calculating a correlation coefficient between the comparative signal and the one-dimensional signal having the section length.
