A gas turbine stator vane is effective for suppressing a secondary flow in a region sandwiched between a suction surface side and a pressure surface side, as well as for suppressing augmentation of a horseshoe-shaped vortex occurring near a leading edge of the vane. The stator vane includes a vane profile portion having a pressure surface concaved to a chord line of the vane, and a suction surface convexed to the chord line; an outer-circumferential end wall positioned at an outer circumferential side of the vane profile portion; and an inner-circumferential end wall positioned at an inner circumferential side of the vane profile portion. An outer-circumferential end wall inner surface that is an inner-circumferential surface of the outer-circumferential end wall has an inward convexed shape and an outward convexed shape, at the suction surface side of the vane profile portion.