A photoacoustic measurement probe and a probe unit capable of preventing generation of artifacts in a photoacoustic measurement apparatus are obtained. In a photoacoustic measurement probe having a light emitting unit that emits measurement light toward a subject, an acoustic wave detection element that detects an acoustic wave emitted from a portion of the subject that has received the measurement light, and a housing which has a surface facing the subject at the time of use and in which the light emitting unit and the acoustic wave detection element are housed, at least one slit that is opened to the housing surface and that extends from the housing surface toward the inside of the housing is provided between the light emitting unit and the acoustic wave detection element.