An object detection apparatus disposed in a moving body generates a transmission signal of multiple pulse sequences as a plurality of sequences of multiple pulses. A modulation signal of the transmission signal is generated by performing digital modulation on each of the multiple pulse sequences of the transmission signal according to a code sequence. A transmission wave based on the modulation signal is transmitted and a reflected wave of the transmission wave is received by the apparatus. The apparatus further detects a speed of the moving body to determine a length of the code sequence. The apparatus calculates a code correlation value between the modulation signal and a received signal, which is derived from the reflected wave, and performs pulse compression on the received signal based on the code correlation value to generate a pulse-compressed received signal. The apparatus detects an object based on the pulse-compressed received signal.