Provided are a measurement probe, a bio-optical measurement apparatus, and a bio-optical measurement system, which are able to prevent, with a simple structure, erroneous connection. A measurement probe 3 has a fiber bundle formed by irregularly bundling a plurality of optical fibers and is detachably connected to a bio-optical measurement apparatus that performs optical measurement on a biological tissue. The measurement probe includes a recording medium 35 that records positional information and items to be examined of the biological tissue in association with each other. The positional information is related to each of positions of an illumination fiber that emits light from a light source 211 of the bio-optical measurement apparatus 2 as illumination light and of a first light-receiving fiber that receives returned light of the illumination light reflected and/or scattered at the biological tissue. The positions are in the fiber bundle at both end faces of each of the illumination fiber and the first light-receiving fiber.