Provided are an optical waveguide for a touch panel which has high light-gathering power on a light-emitting side and which may materialize a touch panel having excellent position detection performance, and a touch panel using the optical waveguide. The optical waveguide for a touch panel includes: cores; and an over cladding layer covers the cores, the cores including light-emitting cores each formed as a lens portion having a shape in plan view including a tapered portion whose width gradually increases toward an end surface on the light-emitting side and an elliptical arc portion which bulges outwardly a tip side of the tapered portion having the gradually-increasing width so as to be in a shape of an elliptical arc, the elliptical arc portion having a major axis direction aligned in a longitudinal direction of the tapered portion.