An optical receiving device includes an optical receiving element and a light collecting portion having an output surface close to or in contact with the optical receiving surface of the optical receiving element. The dispersion plane at an arbitrary point on the line connecting an arbitrary point on an input surface of the light collecting portion to the optical receiving point where light inputted on the arbitrary point on the input surface is received on the optical receiving surface of the optical receiving element is flat, and the normal to the dispersion plane is parallel to the line.