A light detection unit includes a light emitter that emits light toward an object of interest, a light receiver that receives light from the object of interest, and a light blocking member that performs light blocking at least above the light receiver. The light blocking member includes a first surface that is provided between the light emitter and the light receiver and prevents direct light from the light emitter from entering the light receiver and a second surface and a third surface that are provided along a direction that intersects the first surface and prevent light from entering the light receiver. Further, the first surface is made of a first material, and the second surface and the third surface are made of a second material different from the first material.