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 11 having a light emitting unit 40 that emits measurement light L toward a subject, an acoustic wave detection element 20 that detects an acoustic wave emitted from a portion of the subject that has received the measurement light L, and a housing 50 which has a surface 50a facing the subject at the time of use and in which the light emitting unit 40 and the acoustic wave detection element 20 are housed, at least one slit 45 that is opened to the housing surface 50a and that extends from the housing surface 50a toward the inside of the housing is provided between the light emitting unit 40 and the acoustic wave detection element 20.
