In a photoacoustic measurement probe including an acoustic wave detector and an amplifier for amplifying a detection signal of a photoacoustic wave and a probe unit and a photoacoustic measurement apparatus having such a probe, heat is efficiently dissipated from the probe. In a probe (11) having an acoustic wave detector (20) and an amplifier (44), there are provided a first heat conductive member (51) that is in contact with a part of a side plate (50a) of a housing (50) and the amplifier (44) to transfer heat generated by the amplifier (44) to the side plate (50a) and a second heat conductive member (52, 53, 54) that is in contact with a part different from the part of the side plate (50a) and the acoustic wave detector (20) to transfer heat generated by the acoustic wave detector (20) to the side plate (50a).