An optical detection device includes: an irradiation unit that emits irradiation light onto an area formed along a planar area; first and second light receiving units that receive reflection light of the irradiation light reflected by a target object; and a calculation unit that calculates positional information of the target object based on a light reception result of at least one of the first and second light receiving units. A distance between the second light receiving unit and the planar area is shorter than a distance between the first light receiving unit and the planar area, and the first and second light receiving units receive the reflection light that is incident in a direction along the planar area.