A biological information detection apparatus includes a detection unit which has a light receiving unit receiving light from a subject, a light transmitting member which is provided on a housing surface side in contact with the subject of the biological information detection apparatus, transmits light from the subject, and comes into contact with the subject when measuring biological information of the subject, and a diaphragm unit which is provided between the light transmitting member and the detection unit, between the light transmitting member and the subject, or inside the light transmitting member, and narrows light from the subject in an optical path between the subject and the detection unit. The detection unit includes a light emitting unit which emits light to the subject, and the biological information detection apparatus has a light shielding unit which is provided between the light receiving unit and the light emitting unit.
