A trajectory estimation device that includes a waveform generation unit that generates, by using signals based on waves detected by at least three sensors, peak waveforms consisting of time series data of peak frequencies of the signals, a parameter estimation unit that estimates, from the peak waveforms relating to the waves detected by the at least three sensors, a trajectory parameter relating to a trajectory of a moving body having a wave source of the waves, and a trajectory estimation unit that estimates, for all combinations of two of the peak waveforms selected from among combinations of at least three of the peak waveforms, a wave source direction candidate for each of the waves by using the trajectory parameter, and estimate, as a trajectory of the moving body, overlapping trajectory candidates from among trajectory candidates estimated based on the wave source direction candidates.