Provided are a waveguide with a reduced phase error and a photonics device including the same. The waveguide structure may include a lower clad, a core pattern with at least one bending region, on the lower clad, a beam deflecting pattern on the core pattern, and an upper clad covering the core pattern provided with the beam deflecting pattern. The beam deflecting pattern may be formed of a material, whose refractive index may be higher than that of the upper clad and may be lower than or equivalent to that of the core pattern, and the beam deflecting pattern has an increasing and decreasing width or an oscillating width, when measured along the bending region.